ROCK GLACIERS AND PERIGLACIAL ROCK-ICE FEATURES IN THE SIERRA NEVADA, USA;

CLASSIFICATION, DISTRIBUTION, AND CLIMATIC RELATIONSHIPS

Constance I. Millar1 and Robert D. Westfall

7/25/06

Sierra Nevada Research Center, Pacific Southwest Research Station, USDA Forest Service,

800 Buchanan St., Albany, CA 94710, U.S.A.

1 Author for correspondence, [email protected], 510-559-6435

Abstract

Rock glaciers and related periglacial rock-ice features (RIFs) are abundant in the high Sierra Nevada,

California, where they occur in a diversity of forms. From ground-surveys, we mapped 400 RIFs, and propose a regional taxonomic classification based on morphology and position. The classification includes 4 Condition States, 6 Location Classes, and 18 Position Types. Mapped features extended from

2225 m – 3932 m (active, mean 3333 m), occurred mostly on NNW to NNE aspects, and ranged in apparent age from modern (active) to late glacial (relict). To assess modern climate, we intersected mapped locations with the PRISM climate model, adjusting the model results to specific elevations of the

RIFs. Discriminant analysis indicated significant differences among the climate means of the 6 Location

Classes, with the first three canonical vectors explaining 91% of the variation. For active features only, mean annual air temperatures of the Location Classes ranged from 0.57°C to 2.17°C; mean precipitation ranged from 1004 – 1055 mm. We calculated differences between modern and Late Glacial Maximum

(LGM) climates in two ways, one based on elevation differences of paired modern and relict RIFs (662 m) and standard lapse rate, the other using direct PRISM estimates of active versus relict features and assuming differences are stable over time. For the first, we estimate the difference in temperature as

4.3°C (range 2.5° - 7.7°C); from PRISM, the differences were 3.5°C for mean maximum temperature and

1.7°C for mean minimum temperature.

Millar and Westfall 2

Introduction

Rock glaciers and related periglacial rock-ice features (RIF) are widespread landforms in arctic and alpine environments with cold temperatures, low humidities, and abundant shattered rock (White, 1976;

Giardino et al., 1987, Giardino and Vitek, 1988). In the regions where they have been studied intensively, rock glaciers cover as much as 5% (Switzerland; Frauenfelder 2004) to 10% (Chile; Brenning, 2005) of the alpine environment, contain up to 50 to 80% ice by volume (Barsch, 1996a; Brenning, 2005), and contribute as much as 20% (Switzerland; Haeberli, 1985) to 60% (Colorado; Giardino et al., 1987) of alpine erosion. Compared to typical glaciers (referred to as “ice glaciers” in this paper), rock glaciers remain less well recognized and studied. A surge of research attention in the last 25 years has begun to fill the knowledge gap, and both structural and process-level understanding is emerging.

Rock glaciers and related RIFs are especially significant in the context of a warming world. While ice glaciers have been retreating worldwide and in many mountain ranges are predicted to thaw entirely in the 21st century, water contained in the ice of rock glaciers or seasonally frozen ice lenses of RIFs is more protected from thermal changes by insulating rock mantles. As a result, thaw of ice in rock glaciers significantly lags behind ice glaciers, and these features appear to be in disequilibrium with climate, at least when climates are changing rapidly (Clark et al., 1994a; Pelto, 2000; Brenning, 2005). For this reason, rock glaciers are likely to become increasingly critical alpine water reservoirs (Schrott, 1996).

Because these features are rock-covered and can appear similar superficially to rockfalls, talus, and scree slopes, their presence and hydrologic significance have been widely overlooked. In North America, rock glaciers have not been well incorporated into studies that estimate regional distribution and extent of stored ice, assess timing and abundance of mountain streamflows, model changes in water yields under warming climates, or define wetland alpine refugia for biodiversity. In many mountain ranges, rock glaciers remain “…landforms whose wide distribution, occurrence, and significance often go unnoticed”

(Burger et al., 1999).

Rock glaciers and related RIFs are difficult to study due to fundamental properties that resist straight- forward investigation. The internal structure, composition, extent, and dynamics of ice in these features are especially difficult to discern by traditional techniques due to the thick rock overburdens. Further, rock glaciers and related RIFs occur in a wide range of forms, shapes, and topographic locations, with many Millar and Westfall 3 intermediate forms and transitional locations within a mountain range and even within drainages.

Because different researchers have lumped diverse forms together under the term rock glacier, or conversely, considered only very specific forms to be rock glaciers, a range of alternative, often conflicting, hypotheses regarding origins has developed. These include glacigenic versus periglacial processes (summarized in Clark et al., 1998; Burger et al., 1999; Whalley and Azizi, 2003), and for the latter, permafrost versus landslide, avalanche, or other periglacial process (summarized in Johnson,

1983; Whalley and Martin, 1992; Whalley and Azizi, 2003).

Rock glaciers have been investigated for their value as archives of historic glacial activity and paleoclimates in similar ways as ice glaciers. By comparing ages and elevations of active (containing ice) and relict (lacking ice) rock glaciers, and interpreting changes in equilibrium line altitudes (ELA or RILA, rock glacier initiation altitude), timing of glaciations and temperature differences have been determined.

This has led to clarification of Pleistocene (Late Glacial) versus Holocene glacial activity and estimates of temperature differences in the Italian Alps (Baroni et al., 2003), Central Andes of Chile (5.5°C; Brenning,

2005; Trombotto et al., 1997), and Sierra Nevada, California USA (Clark et al., 1994a); of Pleistocene

(Recess Peak) glacial advances in the Sierra Nevada (Clark et al., 1994a); and of late Holocene glaciations in the Swiss Alps (Frauenfelder and Kääb, 2000; Lambiel and Reynard, 2001), Sierra Nevada,

California (Clark et al., 1994a), Rocky Mountains of Wyoming and Colorado (Konrad et al., 1999;

Leonard, 2003; Refsnider, 2005) and Canada (Bachrach et al., 2004). Another approach to estimating

Pleistocene paleoclimates is based on assumptions that rock glaciers indicate the extent of the permafrost zone, which is assumed to require mean annual temperatures of -1 to -2°C or less to develop, and enables comparison of temperature changes over time (2°C, Swiss Alps, Barsch, 1996b;

Frauenfelder and Kääb, 2000; 1.9°C, Japan, Aoyama, 2005) .

Few direct studies have been conducted on modern climate relations of rock glaciers, although comparison with ice glaciers has yielded relative information. In Greenland, Spitsbergen, and Antarctica, active rock glaciers and ice glaciers occur in close proximity. Overall climate was not significantly different between the forms, although rock glaciers occur in distinct topographic locations and slightly drier areas than ice glaciers (Humlum, 1998). In the Japanese Alps, mini-dataloggers placed at the ground surface of rock glaciers recorded temperatures at the bottom of the winter snow cover lower than - Millar and Westfall 4

2°C, despite having a mean annual ground surface temperature above 0°C (Aoyama, 2005). These values were interpreted to suggest that the rock glacier sites are underlain by degrading permafrost.

Brenning (2005) found ubiquitous rock glaciers in the Chilean Andes corresponding with a mean annual temperature of 0.5°C and sporadic intact rock glaciers at regional mean annual temperatures of 4°C.

From these observations, and assuming rock glaciers formed under permafrost climate constraints, he inferred that active rock glaciers were not in equilibrium with current climates, but rather reflect historic conditions. Late 20th century changes in air temperature in Colorado between 1.1° to 1.4°C were estimated to cause an increase in the lower elevational limit of rock glaciers (estimated from permafrost indicators) by 150-190 m (Clow et al., 2003).

External structure and movement of rock glaciers, both glacial or periglacial in origin, have been the subjects of considerable research. Movement has been measured using dendrochronologic analysis of trees being overridden by rock glaciers (e.g., Shroder and Giardino, 1987; Carter et al., 1999; Bachrach et al., 2004), lichenometric assessment of boulder movement (e.g., Osborn and Taylor, 1975; Sloan and

Dyke, 1998), and repeat photography and other photogrammetric techniques (e.g., Osborn, 1975; Clark et al, 1994a; Kääb et al., 1997; Koning and Smith, 1999; Chueca and Julian, 2005; Janke, 2005). The magnitude of movement and velocity of rock glaciers varied, with most estimates in the range of 1-35 cm yr-1 (summarized in Burger et al., 1999; Leonard 2003; Janke, 2005), although repeat photos indicate movement up to 50-60 cm yr-1 in Canada (Osborn, 1975) and Switzerland (Kääb and Vollmer, 2000), and some debris-covered glaciers approach the rate of ice glacier velocities, 0.9 m yr-1 (northern Tien Shan,

Gorbunov and Polyakov, 1992), 1m yr-1 (Colorado, Konrad et al., 1999), and 5m yr-1 (Switzerland,

Vietoris, 1972).

The role of rock glaciers in the hydrologic systems of alpine environments has been studied by various authors (reviewed in Brenning, 2005). Attention has increased with recognition that the matrix of rocks, ice, sediments, and water in a rock glacier functions as a complex aquifer, with recharge, discharge, and through-flow characteristics (Giardino et al., 1992). Unlike the long lag time in response to regional climate change, water flow through rock glaciers responds quickly to daily and seasonal changes in temperature and precipitation (Burger et al., 1997). Johnson (1981) used dye tracers to estimate travel time through a rock glacier in the Yukon Territory, and found times on the order of 0.7 to 2.1 hours. Millar and Westfall 5

Krainer and Mostler (2002) found yearly mean discharge from rock glaciers in the Austrian Alps to be significantly lower than ice glaciers, although the seasonal and daily discharge patterns were similar.

Where studied, rock glaciers are shown to store significant amounts of water for long times (Andes,

Schrott, 1996; Swiss Alps, Haeberli, 1985; Canadian Rockies, Bajewski and Gardner, 1989). Analysis of

3000-4000 active rock glaciers in the Chilean Andes yielded an estimated water equivalent of 0.3 km3 per

100 km2 of mountain area; 21-28% of the area above 3000m drained through active rock glaciers

(Brenning, 2005). In an alpine catchment in Colorado, rock glaciers were the second most important source of groundwater storage, with talus most important, and ice glaciers less (Clow et al., 2003). A similar relative order occurred in the Andes (Brenning, 2003).

Compared to ice glaciers, water discharged from rock glaciers generally has been found to contain lower suspended sediments, higher total dissolved solids, and to be more oxygenated (Johnson, 1981;

Giardino et al., 1992). Williams et al. (2005) analyzed geochemistry of meltwater from a rock glacier in the Colorado Rocky Mountains, and found seasonal differences in geochemistry. Snow was the dominant water source in June; soil water in July; and base flow, estimated to derive from melt of internal ice, in September. These characteristics, in addition to persistent discharge and high volumes, have made rock glaciers important sources of water to mountain communities in some parts of the world

(Andes, Corte, 1999; Brenning, 2006; Boulder, Colorado, Burger et al., 1999). Beyond the terrestrial context, features resembling rock glaciers have been described from the surface of Mars (Kargel and

Strom, 1992; Baker, 2001), suggesting the presence of water and ice on that planet. Interpretation of the

Martian environment hinges on understanding the dynamics, structure, and water-ice-climate relations of rock glaciers and related landforms on Earth.

New remote and geophysical technologies to investigate internal dynamics (e.g., Berthling et al., 1998;

Kääb and Vollmer, 2000; Kääb, 2002; Degenhardt et al., 2003; Janke, 2005) as well as increasing clarity from coring and excavation studies (e.g., Haeberli et al., 1988; Whalley et al., 1994; Clark et al., 1998;

Konrad et al., 1999), are casting light on what had seemed to be an intractable internal structural problem. These studies suggest that multiple morphogenic processes occur, and that their expression varies with local conditions, regional climate, and history. This has led to increasing acceptance of the equifinality of rock glacier origins, i.e., that different initial conditions and processes can lead to similar Millar and Westfall 6 external forms (Johnson, 1983; Corte, 1987a, b; Whalley and Azizi 2003), as well as acceptance that a continuum of landforms can result from similar processes (Giardino and Vitek, 1988; Clark et al., 1994a,

1998; Burger et al., 1999). While this has helped to resolve the polarity of earlier debates, the plurality of origins, convergence of processes, and diversity and continuum of forms mean that research needs to be undertaken on individual types, in specific environmental settings, and with known histories before systems-level understanding can develop.

The equifinality of rock glacier origins and forms has helped clarify approaches to nomenclature and classification. Although many papers have discussed terms and definitions and offered general classifications (summarized in Johnson, 1983; Corte, 1987a; Hamilton and Whalley, 1995; Whalley and

Azizi 2003), it is clear now that the most useful classifications are based on morphology and location rather than assumed origins (Hamilton and Whalley, 1995; Whalley and Azizi, 2003). Further, the diversity of forms and dependence on regional conditions make clear that generalized definitions, important as starting points, are inadequate for intensive or regional research. Rather, site-specific descriptions, nomenclature, and classifications have been called for to promote accurate mapping exercises, climatalogical investigations, and process-based studies (Hamilton and Whalley, 1995).

To date, no specific regional classification has been published, and the available inventories rely on generalized descriptions of basic types. Commonly used terms based on morphology and location include “valley-floor” versus “valley-wall” rock glaciers (Outcalt and Benedict, 1965); as well as “tongue- shaped” versus “lobate” (Wahrhaftig and Cox, 1959). Several authors distinguish between “rock glaciers”, that is, features having steep fronts, steep sides, length greater than width, and existing on a valley floor, and “protalus lobes and protalus ramparts”, with similar morphology but occurring on valley walls, in front of talus slopes, and generally wider than long (Martin and Whalley,1987; Hamilton and

Whalley,1995; Whalley and Azizi, 2003).

Based on these general terms, and sometimes using genetic definitions implying processes of origin such as debris-covered glaciers, ice-cored glaciers, or permafrost rock glaciers, local inventories have been made in several regions of the world. These include the Arctic (Svalbard, Berthling et al., 1998;

Greenland, Humlum 1997; Alaska, Wahrhaftig and Cox, 1959; Calkin et al., 1987; Yukon, Johnson, 1978,

1987; Blumstengel, 1988); Antarctica (Strelin and Sone, 1998; Serrano and Lopez, 2000), New Zealand Millar and Westfall 7

(Brazier et al., 1998); European Alps (Evin, 1987; Haeberli et al, 1988; Smiraglia, 1992; Francou and

Reynaud, 1992; Von der Muehll and Klingele, 1994; Guglielmin et al., 1994; Palmentola et al., 1995; Lieb,

1998; Pancza, 1998; Serrano et al, 1999, 2001; Frauenfelder et al., 2003); Tien Shan (Titkov, 1988; Cui and Zhu, 1989; Gorbunov and Polyakov, 1992); Himalayas (Barsch and Jakob, 1993); and Andes (Corte,

1987b; Schrott, 1996; Kammer, 1998). Because the classifications used were generalized, however, the resulting inventories either focus on a few specific forms or cluster diverse features together, making further analysis of the diversity of forms difficult.

In temperate western North America, inventories have been made for a few local areas, including

Galena Creek, Absaroka Mtns, Wyoming (Potter, 1972), the Colorado Rockies (White, 1971, 1987;

Giardino, 1979; Benedict et al., 1986; Vick, 1987; Giardino et al., 1984; Degenhardt et al., 2003; Janke,

2004), Canadian Rockies (Johnson and Lacasse, 1988; Sloan, 1998), and La Sal Mountains of Utah

(Shroder, 1987; Morris, 1987; Parson, 1987; Nicholas and Butler, 1996; Nicholas and Garcia, 1997).

In the Sierra Nevada, California, limited information exists on the rangewide distribution of rock glaciers, although focused studies on paleoclimate and glacial advances have been conducted on a subset of glacigenic (debris-covered) rock glaciers in the range (Clark et al., 1994a; Konrad and Clark,

1998). A few Pleistocene relict rock glaciers are indicated on high-resolution geologic maps of the Sierra, and anecdotal observations suggest that rock glaciers and related RIFs are abundant in cirques and canyons of the Sierra Nevada south of Lake Tahoe. Aside from Clark and his students’ research, however, no regional classification or mapped inventories have been developed. Beyond the few glacigenic features they have studied, the distribution, extent, and significance of rock glaciers in the

Sierra Nevada are little known, and these features remain widely overlooked.

GOALS

We undertook the work described here to expand the geographic and climatic knowledge of rock glaciers and related RIFs in the Sierra Nevada. In particular we present information about their location, abundance, extent, and climate relations in the hope it will assist analysis of RIF water-storage capacities and encourage incorporation into future climate-scenario assessments. We include a wider range of features in our classification than is usually discussed in rock glacier contexts to highlight potential Millar and Westfall 8 physical and genetic interrelationships and to suggest possible hydrologic significance of overlooked forms.

Relative to rock glaciers and associated periglacial RIFs in the Sierra Nevada, the goals of the present study were to:

• Develop a regional taxonomic classification and nomenclature;

• Compile a geo-referenced database with type localities and photos derived from field-mapping;

• Analyze geographic and climatic relations (modern and historic) of the mapped rock-ice features.

Methods

MAPPING AND CLASSIFICATION

During the field seasons of 2000 through 2005, we observed and mapped “classic” rock glaciers and associated RIFs in the Sierra Nevada from Sonora Pass in the north to Cottonwood Pass in the south

(Fig. 1), focusing on the region between Robinson Cr., Bridgeport area, and North Fk. Bishop Cr., Bishop area. We mapped features at locations and elevations where glacial and periglacial processes appear to dominate, and whose form and structure suggested glacial or periglacial origins – e.g., features that have been described as rock glaciers (including debris-covered glaciers); active moraines; protalus lobes and ramparts; creeping scree slopes; solifluction slumps; patterned-ground circles, nets, stripes; and other undescribed forms. Ice glaciers and persistent snowfields without associated decomposed rock mantling were not included. Each feature was field-mapped visually at coarse resolution on topographic maps and later characterized with digital maps (National Geographic, 2004) for latitude and longitude (center of feature), elevation range, and local slope aspect. Feature size was described in four ranks (400 ha,

50ha, 5 ha, 0.5 ha); three shape ranks were scored (wider than long, approximately equal length and width, longer than wide).

While not part of the classification, we made preliminary determinations of activity, following conventions previously observed (e.g., Ikeda and Matsuoka, 2002). Current activity (embedded ice, movement) is difficult to determine by casual observation; a feature was tentatively scored active if it was:

1) within the elevation range of local ice glaciers and persistent snowfields; and had 2) oversteepened front and sides relative to the ambient slope (certain types only; see descriptive taxonomy section); 3) Millar and Westfall 9 angular rocks with no or little lichen growth; 4) plant cover absent or minimal; 5) appearance of active sorting of clasts, and 6) persistent spring or stream, or presence of phreatophytes (e.g., Salix, Carex) at the feature’s downhill front or sides. Whereas other authors have further classed features as inactive

(ablating ice-core or ice matrix) and relict (ice lacking), we did not feel capable of discerning these differences, and we rated features only as active or relict. For relict features, we made a tentative assignment of age, based on appearance, elevation, and size, as Holocene, Pleistocene-Recess Peak

(Clark et al., 1994a; Clark and Gillespie, 1997) and Pleistocene-Last Glacial Maximum; these ages are proposed as hypotheses awaiting confirmation from intensive research and/or new technology.

Based on observations of ~300 features, a preliminary taxonomy and nomenclature were developed.

The classification was based on current condition and form of features (morphology), not origins, and on field-visible conditions without reference to subsurface conditions, internal processes, or other aspects that require special measurement to determine. We followed the guidelines for classification outlined by

Hamilton and Whalley (1995), as well as precepts borrowed from biological classification. These include: relationships are hypothesized by hierarchic levels and adjacency of groups, and nomenclature reflects the implied relationships. Categories in the classification are distinct and non-overlapping, but this does not preclude the common occurrence of intermediate or complex features in the field that are difficult to classify. The classification is not intended to be comprehensive of periglacial or glacial features, especially of periglacial forms that are unlikely to store significant water or ice. Although not part of the classification, we speculate on potential origins (glacial/periglacial/permafrost-related) of the major categories in the hope these can be tested in further studies.

The preliminary taxonomy was tested by revisits to ~20% of the originally mapped features, and by the addition of ~100 new features, which led to the revised taxonomy and nomenclature presented here.

Henceforth in this paper we refer to features either in general as RIFs, or we use the specific names from our classification.

CLIMATE MODELING

Location data for all mapped RIFs were imported into GIS (Arc Info) as point coverages

(latitude/longitude of centers). These groups were intersected with data from the 4 km2 gridded PRISM climate model (Daly et al., 1994). From that set, we extracted layers for annual, January and July Millar and Westfall 10 minimum and maximum temperatures, respectively; and annual, January, and July precipitation, respectively, for the period of record, 1960-1999. The PRISM grids were converted to polygons and sequentially intersected with the locations of the RIFs, grouped by the six taxonomic Location Classes

(see Results, Table 1). To adjust the mean climate values of each 4 km2 PRISM polygons to the specific elevations of the RIFs we followed the approach of Hamman and Wang (2005). For this, we used 30 m digital elevation model (DEM, from Davis et al., 1998) tiles for the eastern Sierra Nevada ecoregion, and intersected these with climate data from the PRISM 4 km2 model, extracting the PRISM climate data with latitude, longitude, and elevation. We then regressed response-surface equations of latitude, longitude, and elevation of the DEM tiles against the PRISM tiles. Rather than using regression equations of

Hamann and Wang (2005), which were based on Canadian locations, we used modified multi-order response-surface equations of the form:

(latitude + longitude)n + elevation + elevation x (latitude + longitude)n-1 where > 90% fit was obtained when n, the order of each equation, equaled 3 to 5 for the temperature data and 5 for the precipitation data. As in Hamann and Wang (2005), we took the first derivative for elevation in each equation to estimate lapse rates for climatic data by elevation to adjust temperature and precipitation between the mean elevation of the 4 km2 PRISM tile to each RIF feature. Surface analysis regressions were done in JMP (SAS, 2002), and first derivatives were computed in Mathematica

(Wolfram, 2004).

To determine differences among Location Classes, we subjected the merged RIF/PRISM-climate data to discriminant analysis. We classified the analysis by Location Class with the climatic measures as variables, maximizing RIF differences in multivariate climate space. We then computed mean & variance climatic data from the PRISM model for the classified groups.

We made preliminary assessments of climate differences between modern and Pleistocene conditions using two approaches. First we extracted a subset of RIFs that included pairs (or groups) of active and

Late Glacial Maximum (LGM)-scored features from the same drainages, and calculated the differences between the lower elevations of each feature. For the first method, we multiplied the elevation difference by a standard lapse rate, -6.5°C/km (Wallace and Hobbs, 2006), which Lundquist and Cayan (2006) verified from 38 weather stations as highly accurate for mean annual temperatures of high elevations in Millar and Westfall 11 the central Sierra Nevada. For the second method, we calculated modern PRISM climate means for each pair (or group) of RIFs, adjusted by elevation to the selected RIFs. We used differences in these means to represent differences between the modern and LGM conditions, assuming lapse rates have not varied over time. From these PRISM results, we can also estimate lapse rates directly to compare with the standard rate.

Results

CLASSIFICATION AND MAPPING

We mapped 400 RIFs (Appendix 1) and propose a tentative taxonomic classification and nomenclature for the Sierra Nevada (Table 1). The classification describes three hierarchic levels within the overall group, Rock-Ice Features. These include 4 Condition States, 6 Location Classes, and 18

Position Types. Condition States are the highest level (primary category) within the classification and separate the major geomorphic types; Location Classes describe location of RIFs within each Condition

State; and Position Types are the terminal categories. Type localities for each Position Type are identified (cross-reference Table 2 and Appendix 1), and each Type is illustrated (Figs. 2-5). Further images will be available at: http://www.fs.fed.us/psw/cirmount/wkgrps/hydro/

Summary of Categories

Mean values for geographic location, size, and shape are given for the overall Group, Condition

States, and Location Classes in Table 2; slope aspects for the six Condition States are indicated in Fig. 6.

Below we summarize each category in the classification.

Group: Rock-Ice Features (RIFs): Distinct high-mountain landforms comprising sorted, angular rock debris; landforms appear to move collectively by gradual surface movement and not catastrophic displacement (e.g., avalanche or rockfall); rock debris are reversely sorted (fines low or missing; coarse high); landform edges are typically abrupt but in a few forms gradual. Some forms are characterized by oversteepened fronts and/or sides relative to the ambient slope, and the tops of nearly all forms have lower slope angles than the gravity-fall angle of the ambient slope. Features may be active or relict (as defined in methods). Individual rocks are not marked by fresh abrasion as characterize recent avalanche or rockfall debris; insignificant amounts of embedded material (soil, plant stems, etc) are entrained in Millar and Westfall 12 active RIFs. Occasional steep-sided sink-ponds (karst or meltponds) occur in the rock mantle of some forms, revealing massive and stratified underlying ice. In others running water can be heard in summer below the surface.

Potential Origins: Both glacial and periglacial processes appear involved, varying by individual feature. Permafrost and/or seasonally frozen ground with freeze-thaw action is likely necessary for origin of some forms; others appear to derive from ice glaciers; and others yet appear to originate from cumulative snow-, ice-, and rock-fall events. Multiple processes appear likely to yield similar forms; conversely, similar processes appear to give rise to different forms depending on environment and micro- climate.

The 400 RIFs mapped in the Sierra Nevada extended from 38.2836˚N, near Sonora Pass, to

36.4845˚N, near Cottonwood Pass, and had a mean elevation of 3295 m (range 2225-3932 m; Table 2).

We estimated 75% to be active features; these had a higher mean elevation (3333 m; range 2673-3932 m) than the overall group. Overall the mean size of the features was 15 ha, with about equal distribution among the three shape categories; primary aspects were northern, although features were mapped in all primary coordinates (Fig. 6).

Condition State: Rock Glaciers/Rock Periglaciers (RG/RPG): Simple or complexly lobed, discrete landforms with abrupt edges, oversteepened fronts and sides, and overflattened tops relative to the ambient slope. Ice is rarely visible except in occasional meltponds (karst ponds) where massive, laminated ice bodies may underlie a rock debris mantle, or in persistent snow/icefields that adhere to cirque or cliff walls above the RIF. Features may occur within cirques, extend from cirques into valley floors, or occur on valley walls, in the midst of scree slopes, in talus cones, or beneath cliffs or avalanche chutes. Adequate quantities of decomposed bedrock or other coarse debris (till, frost-shattered rock) are available above the feature to supply rock mantle/matrix.

Potential Origins: Glacial (rock mantling on clean glaciers); periglacial (transiently [multi-year] stable and/or seasonally persistent ice interacting with shattered rock masses). Potentially interchangeable

(e.g., ice glacier to Rock Glacier/Rock Periglacier) as climates change. Permafrost (or transiently frozen ground) may be involved in some features. The terms “rock glacier” and “rock periglacier” are used to emphasize that glacial and/or periglacial origins may be involved. Millar and Westfall 13

We mapped 265 Rock Glacier/Periglacier features, which ranged from 2225-3932 m; 68% were active

(Table 2). Shape and size varied by Position Type, but this category included the largest forms mapped as well as relatively small forms.

Location Class: Cirque Rock Glaciers/Periglaciers (RGC). Features originate in high cirques and are contained either within the cirque (cirque wall or floor) or emanate downvalley as complexly lobed, elongate bodies of rock debris; features may also develop from ice-glacier terminal moraines either within or outside the cirque. Features may begin with an icefield (glacierette) or persistent snowfield in the cirque. Flow parallels the valley axis, and fronts generally are perpendicular to axis. We mapped 169

RGC features, having mean elevation of 3324 m (active, 3390 m) and mean size of 20 ha; more features were long or equal length-to-width than wide; and 67% were active (Table 2). RGC features were oriented predominately north, with northeast aspects also common (Fig. 6).

i. Cirque Wall, RGC-Cq. Features are contained within cirques and occur on cirque walls or as complexly lobed features extending onto cirque floors (Fig. 2a). RGC-Cq features tend to be wide or equal width-to-length in shape, and typically cover less than 50 ha. This type includes some of the highest elevation features mapped.

ii. Valley, RGC-Va. Features originate in cirques but emanate into valleys or slopes beyond cirques (Fig. 2b). Occasional RGC-Va features have no remaining presence within the cirque, and occur only below cirques. Features are always longer than wide, and include some of the largest features mapped (>50 ha). Active features may begin with ice fields in the cirques and terminate in lakes whose waters are opaque from suspended fine sediments, or may have active streams that either surface or remain below (or within) the rock matrix. Relict features (scored as Pleistocene) extend many km downhill, cover up to 400 or more ha, and reach the lowest elevations (2225 m) of any features mapped.

iii. Moraine, RGC-Mo. While ice-glacier terminal moraines are relatively thin, arcuate landforms with unsorted till, RGC-Mo features emanate from such moraines and flow downhill with typical RGC form

(sorted debris, oversteepened fronts and sides) (Fig. 2c). These features are generally among the highest elevations of features mapped in the Sierra Nevada. Shapes are typically wider than long, and sizes are less than 50 ha. Millar and Westfall 14

iv. Pocket, RGC-Po. A rock glacier/periglacier that occurs in a small recess or niche in the terrain

(Fig. 2d). Otherwise, form and features are similar to Cirque Wall features, RGC-C.

Location Class: Valley Wall Rock Glaciers/Periglaciers (RGV). Relatively small features, compared to

Cirque Rock Glaciers/Periglaciers, that originate on valley walls as short to wide bench-like structures, flow downslope toward the valley bottom, and have fronts that parallel the valley axis. Valley wall features occur along scree slopes, within talus cones, and below cliffs or avalanche chutes. We mapped

96 RGV features, which had mean elevation of 3243 m (active, 3292 m) and mean size of 3 ha; 61% of the features were wider than long in shape; and 69% were scored as active (Table 2). RGV features occurred on predominately north and northwesterly aspects (Fig. 6).

i. Avalanche, RGV-Av. Valley wall features that are located under avalanche chutes (Fig. 3a).

ii. Talus Cone, RGV-Ta. Valley wall features that are located within talus cones (Fig. 3b).

iii. Scree Slope, RGV-Sc. Valley wall features that are located within scree slopes (Fig. 3c). These were the most common of the RGV types mapped.

iv. Cliff Slope, RGV-Cl. Valley wall features that are located below cliffs (Fig. 3d). RGV-Cl features occassionally occurred below cliffs at the terminus between two adjacent valleys. In these cases the features were wedge-shaped, due apparently to the arc of shade cast from these locations and the resulting triangular cold zone.

Condition State: Boulder Streams (BS): Landforms similar to Rock Glacier/Rock Periglaciers, dominated by sorted, shattered rock, but lacking oversteepened fronts or sides. Boulder Stream front boundaries instead occur where large sorted boulders (angular, lichen-free, and without recent abrasions) abruptly meet deep, wet, organic soils supporting mesic “turf” vegetation that appears to be rolling (carpet like) over the landform front. The landform appears to move downslope collectively without turbulence to the rafting rocks. Boulder Streams occur on slopes and valley walls in similar topographic locations as RGV features, and rarely in cirques. Some large features cover entire mountain slopes; very small Boulder

Stream types (e.g., BSC-Sn) may occur below snowfields on gentle slopes, or along stream-courses in valley bottoms or low-gradient slopes. Abundant sources of decomposed rock and coarse debris (till, frost-shattered rock) occur above the features and appear to supply rock mantle/matrix. Running water is Millar and Westfall 15 often heard below the rocks. Springs, boggy grounds, fringing phreatophytic growth, and persistent ponds or lakes are common at Boulder Stream fronts.

Potential Origins: Periglacial; transiently [multi-year] stable and/or seasonally persistent ice interacting with shattered rock masses. Permafrost (or transiently frozen ground) processes may be involved for sorting and movement and to form the distinctive boundaries at the fronts and sides of these features.

Avalanching may also contribute snow and ice to these features.

We mapped 93 Boulder Stream features, which ranged from 2743-3780 m; 94% were active (Table 2).

Shape varied by position type, and this category comprised relatively smaller forms (less than 5 ha) than

RG/RPGs. Aspects included all primary cardinal directions, with south as well as north common. Some features (especially stream course features) had very low relief. The Boulder Stream Condition State is divided into two Location Classes depending on whether they follow a defined stream-course or not.

Location Class: Scree Slopes (BSC). Boulder Streams that occur on valley walls and other slopes of steep to low gradient. These features range from very large (entire slopes) to very small (below persistent snowfields). While running water is often heard below the surface, it is diffuse across the feature, not concentrated as in a stream course. We mapped 71 BSC features, which had a mean elevation of 3253 m (active, 3245 m), and mean size of 4.8 ha (Table 2). Most BSC features were longer than wide or had about equal width and length. The Boulder Stream position types are in similar locations to the RG/RPG group, although they may be lower in elevation and occur on a wider variety of aspects (Fig. 6).

i. Avalanche, BSC-Av. Boulder Streams that develop in debris under relict avalanche and rock-falls

(Fig. 4a). Boulder Streams appear to develop only in certain cases (aspect, elevation) and do not show signs of continuous or recent avalanching on their surfaces.

ii. Talus Cone, BSC-Ta. Features develop from rock debris in talus cones on valley slopes (Fig.

4b).

iii. Scree Slope, BSC-Sc. The most common form of Boulder Streams in the Sierra, occurring on cold, sheltered scree slopes (Fig. 4c).

iv. Snowfield Apron, BSC-Sn. Small Boulder Streams with irregular shapes (often teardrop-like) that form near the base of persistent snowfields (Fig. 4d). Millar and Westfall 16

v. Cliff, BSC-C. Boulder Streams similar to talus cone and scree slope features, except occurring on slopes below cliffs (Fig. 4e).

Location Class: Stream Courses (BST). Boulder Streams that follow stream courses, either on slopes or in valley bottoms; slopes vary from moderate to very low gradient (Fig. 4f). We mapped 22 BST features, which had a mean elevation of 3228 m (100% mapped were active), and mean size of 2.4 ha

(Table 2). Most BST features are elongate and narrow. Running water is often heard below the surface as a concentrated stream; the stream itself may surface and submerge many times.

i. Stream Course. Only one Position Type is defined, hence its description matches that of the

Location Class.

Condition State: Patterned Ground (PG): Landforms similar to Boulder Streams but are associated with standing water or saturated soils, rather than running water, and usually are small to very small in size.

Features are distinctly bounded, with sorted rock (angular, no lichens or soil) abruptly meeting weathered soil surfaces. Patterned Ground Circles and Mass Waste features may have weathered soil within the features’ boundaries. Features occur on very high, exposed, often windswept, snow-free plateaus, benches and slopes; some features bound alpine lake margins at locations that may be submerged during spring melt. Many forms of patterned ground (nets, stripes, circles) have been described elsewhere, and we adopt conventional nomenclature as possible for consistency (Washburn, 1956). A feature was considered active when it had abrupt boundaries, and rocks were angular with no lichen growth. We did not extensively search for PG landforms, and mapped them opportunistically.

Nonetheless, as they appear associated with periglacial processes, we include them in the classification to suggest possible relationships. Further, because their climate relations have been relatively widely studied, where patterned ground features co-occur with rock glaciers, rock periglaciers, or boulder streams, they may provide inferences about local climate.

Potential Origins: Periglacial (permafrost and/or seasonally frozen ground processes, e.g., freeze- thaw, convection, contraction).

We mapped 15 PG features; the mean elevation was 3273 m, 73% were mapped as active. PG features were the smallest in size of all categories, averaging 1.1 ha. Shapes were mostly equally wide Millar and Westfall 17 as long, although irregular length and width features also occurred. Many occurred on flat benches and lake margins, although northerly slopes were favored (Fig. 6).

Location Class: Alpine Flats & Slopes (PGA). Only one Location Class is defined within PG, hence it’s description matches that of the Condition State.

i. Lake Margin, PGA-La. Small patterned-ground formations, usually circular or sub-circular although occasionally irregular, occurring at margins of high lakes or tarns (Fig. 5a). Features commonly are < 3 m diameter.

ii. Circles, PGA-Cr. Circular landforms, ≤ 1-2 m diameter, that occur on flat or very gently sloping high plateaus and benches (Fig. 5b). These are the only features mapped in the entire database that are defined by developed soil on the main portion of the feature (interior of the circle) and having a sharp boundary of sorted rocks at the circle’s edge. The transition from soil inside to the sorted rock edge and from the sorted rock edge to the adjacent matrix ground is abrupt in active features.

iii. Nets, Stripes, PGA-NS. Irregular strips and elongated polygons of sorted, angular rocks, fines missing, having abrupt landform boundaries with adjacent weathered soils, occurring on gentle to moderate slopes. These patterned ground forms have been described in the literature as developing similarly to circles (freeze-thaw, convection) but on slopes, where gravity pulls the feature into elongate circles and eventually nets and stripes (Fig. 5c) that may contain long, narrow polygons. These also occur only on high, dry, exposed environments.

Condition State: Mass Wasting (MW): High, exposed, and relatively low gradient alpine slopes comprising complex slumps and hummocks that appear to creep downslope. The only forms defined in this condition state were on Alpine Slopes & Flats and of apparent solifluction morphology. These are complexly hummocked with reversely sorted structure in each hummock. Individual hummocks may have oversteepened fronts relative to the general slope, but these are not abrupt as in Rock Glaciers/

Periglaciers. Some soil may be developed on active features, unlike those in the Rock Glacier/Periglacier or Boulder Stream categories. These features do not appear to be reservoirs of large ice masses or rock-ice matrices such as Rock Glaciers/Periglaciers or Boulder Streams are likely to be. Because they cover large areas, however, and may be associated with permafrost or seasonally frozen ground, their hydrologic significance may be important. As with patterned ground, we mapped these features Millar and Westfall 18 opportunistically, so the number and distribution listed here are less than their representation on the ground. These are large features, and occur at the highest mean elevations of all categories mapped.

Potential Origins: Periglacial: downslope movement of saturated soils interacting with permafrost, transiently frozen ground, or slick bedrock.

We mapped 22 Solifluction Field features, averaging 3509 m elevation, 100% active, with mean size

15 ha; almost all were about as wide as long, and orientations were diverse (Fig 20).

Location Class Alpine Slopes (MWA) and Position Type Solifluction Field (MWA-So). Because there is only one Position Type, descriptions of the Class and Type are the same as for the Condition State

(Fig. 5d).

CLIMATE

Discriminant analysis of PRISM climate data indicated significant differences among the six RIF

Location Classes. The first three canonical vectors (CV) explained 91% of the variation (48%, 29%, and

14%, respectively); the first two were significant at p < 0.001. Correlations of the CVs to the climate data indicated strong associations (correlations > 0.5) for January maximum temperature (CV 1), July and

January maximum temperatures, July minimum temperature, annual minimum temperature, and July precipitation, (CV2), and July precipitation (CV3) (Table 3). The six Location Classes separated distinctly in the plot of canonical scores (Fig. 7), which indicates means and 95% confidence intervals for the means (ellipses) for each Class. Classes MWA, RGC, and RGV separated on CV1, and those three

Classes separated from BSC and BST on CV2. The largest scatter of points was for Class PGA, which distinctly separated only from MWA on both CVs.

Mean climate values derived from the elevation-adjusted PRISM climate model and grouped by the six

Location Classes are shown in Table 4, which includes only active RIFs east of the Sierra crest (n=294).

Based on mean annual temperature, the coldest class of RIFs was MWA, at 0.57°C. The Rock Glacier/

Rock Periglacier classes, RGC and RGV, were in warmer environments, 0.9°C and 1.0°C, respectively.

The Boulder Stream classes, BSC and BST, had the highest means, 1.72°C and 2.17°C, respectively.

This order among the Classes was similar for the other temperature variables, except for July minimum temperature, where MWA had the third coldest mean temperature, and RGV and RGC had lower values. Millar and Westfall 19

Mean annual precipitation of the Location Classes ranged from 1004 mm (BSC) to 1055 mm (RGV)

(Table 4). PRISM indicated that most of the precipitation falls in winter, but a significant amount also occurs during summer at these elevations.

Based on differences in base elevations of paired active versus relict RIFs, we calculated temperature differences between modern and Pleistocene Late Glacial climates (Table 5). Using the standard lapse rate (-6.5°C/1000 m) and the average elevation difference among the select paired RIFs (662 m), on average Pleistocene annual temperatures were 4.3°C colder than present (range, 2.5° to 7.7°C). Using the PRISM model (and its inherent lapse rates) to directly infer modern temperature differences between the elevations of the active and relict RIFs, the calculated differences between modern and Late Glacial temperatures were less and more variable than those using the standard lapse rates. The mean maximum temperature difference was 3.5°C colder (range, 0.3° to 8.0°C) and mean minimum temperature difference was 1.7°C colder (range, 0.3° to 4.8°C) (Table 4). Lapse rates smaller than the standard value resulted from this method (mean -3.6°C/1000 m, range -1.9° to -5.8°C/1000 m).

Discussion

CLASSIFICATION, MAPPING, AND DISTRIBUTION

Our classification differs from others by its regional character, proposed taxonomic hierarchy implying relationships, larger number of terminal categories, inclusion of a more diverse group of RIFs, and development from a database of specific mapped features. In so doing, it follows recommendations of previous researchers (Corte, 1987a; Hamilton and Whalley, 1995; Whalley and Azizi, 2003). When initially mapping features in the field, our intent had been to limit the inventory to forms that traditionally have been considered rock glaciers and protalus ramparts. We found, however, that definitions in the literature were inadequate to describe the range of features in the environments of the Sierra Nevada.

For example, for features conventionally considered “rock glaciers”, (e.g., Wahrhaftig and Cox, 1959;

Hamilton and Whalley, 1995) we found that distinctions of “valley floor” (also called “tongue-shaped”) versus “valley wall” (also called “protalus ramparts” or protalus lobes”) did not describe the forms and shapes that occurred within cirques (some of which were lobate; others tongue-shaped; others complex or different forms; some extending out of the cirques, others not; some associated with terminal Millar and Westfall 20 moraines); did not distinguish between the fact that nearly all features with oversteepened fronts (our

RGC and RGV classes) were, within some degree, in front of talus (i.e., were “protalus”), some of which were elongate and others wide and “ramplike”; and did not adequately fit the forms that were tongue- shaped but extended below valley wall or cirque cliff faces, especially at the junction of canyons. Other

Sierran forms, although mentioned in the literature, did not fit generalized classifications at all, such as features that develop from ice-glacier terminal moraines (e.g., Clark et al., 1994a, 1994b; Corte 1999;

Whalley and Azizi, 2003), or from pocket or niche glacier locations, which are relatively common in the

Sierra Nevada.

The Sierra Nevada has a warm Mediterranean and semi-arid climate where decomposed rock is abundant, especially along the metamorphic exposures of the eastern escarpment. Modern ice glaciers are small and few in number and persistent snowfields are similarly small and scattered. Thus, while rock glaciers and related RIFs are common in the Sierra, they tend to be smaller in nature and occupy more diverse environments than appears to be the case for mountain ranges that receive greater precipitation and are located in cool-humid climates. These features of the range may contribute to the diversity of forms that does not fit generalized definitions.

Further, the use of “rock glacier” versus “protalus ramparts or lobes”, as well as terms such as “debris- covered glacier” imply origin pathways (glacial versus periglacial) that we feel is difficult or impossible to discern for most situations in the Sierra Nevada. We based the classification instead on form and location, as has been recommended elsewhere (Outcalt and Benedict, 1965; Corte, 1987a; Hamilton and

Whalley, 1995; Johnson, 1983; Burger et al., 1999). The term “debris-covered glacier” is a useful description of situations where a known ice glacier becomes covered with debris. This phenomenon is known to occur both during times of glacial growth, for instance within local areas of rockfall, and especially during paraglacial times, when ablation exceeds accumulation, and debris from rockfall accumulates (Benn and Evans, 1997; Ballantyne, 2002). Thus, the definition of an ice glacier adequately encompasses conditions where debris accumulates on ice. As we did not include ice glaciers in our classification, we did not use the term “debris-covered glaciers”, nonetheless recognizing that these glaciers may convert over time into features such as we have termed Rock Glaciers (RG) (Clark et al.,

1994a; Ackert, 1998). Millar and Westfall 21

In encouraging consistency of terms in regard to process, we offer in the nomenclature the combined label “Rock Glacier (RG)/Rock Periglacier” (RPG). We do this to stress that a feature could be glacial or periglacial, and also to recognize that with time, new technology and new research will likely determine the origins of specific features, and then the more accurate name can be assigned. By “periglacial”, we adopt the convention to include the cold environment extending around an ice glacier, and also areas of low temperatures where glaciers never existed (Hamelin and Cook, 1967). Periglacial environments encompass a range of processes that depends on the presence of water and repeat freezing and thawing. Periglacial environments are often underlain by permafrost, but its presence is not a requirement (Washburn 1956; 1980; French, 1996; Ballantyne, 2002), and we do not imply the presence of permafrost in the Sierra, although it may occur. Diverse landforms resulting from periglacial processes are well known, and we selected for our classification only those that appeared related to rock glaciers, and those where subsurface water is essential to pattern formation and thus of hydrologic interest.

We included more terminal categories (Position Types) than other classifications with the intent of highlighting the range of conditions that RIFs inhabit in the Sierra Nevada, and to encourage research attention on the diversity of forms. Until more is known about the origins and processes involved in their development, it is useful to separate and recognize distinct categories (“split”) rather than confound the forms by clustering diverse landforms into single heterogeneous categories (“lump”). Considering our

Location Class RGV, for instance, it is possible that features which develop under avalanche chutes

(RGV-Av) may originate differently from those within talus cones (RGV-Ta), and these may have different origins than features developing within scree slopes (RGV-Sc) or under cliff faces (RGV-Cl). Dynamics of snow- and rock-fall, avalanching, debris flow, frozen-ground processes, water drainage, and persistent snowfield accumulation differ by location, and thus likely the origin and processes involved with these features depend on their unique environments (Johnson, 1983; Corte, 1999). That we distinguished significant differences geographically and climatically among the Location Classes further suggests that these forms are separable and can be classed uniquely. At the same time, we acknowledge the continuum nature of these environments. If subsequent research indicates that similar processes and origins describe several of our position types, the categories can then be collapsed. Millar and Westfall 22

In addition to rock glaciers and related types in the classification, we introduce other RIFs not usually considered within a rock glacier context. Landforms such as our Location Class of Boulder Streams have been little discussed in the literature as discrete rock-ice features. Features with similar characteristics have occasionally been described as block fields (especially when associated with patterned ground processes (Harris et al., 1995; Ballantyne, 1998), although the Boulder Streams of our classification seem to bear little resemblance to the processes or forms of typical block fields. It is likely also that previous studies of water-bearing talus fields have included landforms that we describe as Boulder Streams (e.g.,

Johnson, 1983; Clow et al., 2003). These features are difficult to portray in photographs, but their distinguishing characteristics in the field (as described in the classification) are striking, and they are readily separable from commonly occurring dry, talus cones, scree slopes, and rockfalls.

Compared to the Rock Glacier/Rock Periglacier group, active Boulder Stream features in the Sierra regularly have as much or more apparent water associated with them. Running water below the surface is obvious and widespread; outlet springs, streams, and ponds are common, large, and persistent; and phreatophytes commonly fringe their bases. Freeze-thaw cycles of water-saturated matrices (soil or rock) in adjacent and subsurface soils of the BSC features likely contribute to the sorted rocks and the characteristic pattern of the landform “diving” under -- or pushing forward -- dense, humic soils at the lower edges. The nature of their water storage and potential movement – whether ice-matrix derived from avalanche, frozen-ground processes derived from discontinuous permafrost, or other (Williams

1983; Mackay, 1983) – is enigmatic. These features seem important to highlight, however, because they are often overlooked yet appear to be significant hydrologically.

Patterned ground and related permafrost features are common in arid, cold climates of the world

(Washburn, 1980; Ballantyne, 2002). While they have been observed anecdotally in the Sierra Nevada, no focused studies exist that we know. Tacitly they are considered relict features, as permafrost is assumed not to exist in the range. Intensive research in the adjacent White Mountains of California, however, has demonstrated the presence of discontinuous active patterned ground features and processes at 3800 m; above 4150 m active patterned ground processes become the dominant landscape phenomena (Wilkerson, 1994; 1995). Freeze-thaw cycles throughout the year are common in some parts of the White Mountains, with over 220 cycles per year observed (LaMarche, 1968). Wilkerson (1994; Millar and Westfall 23

1995) defined abundant active sorted circles, nets, and stripes, and studied the movement and soil processes of frost boils and other permafrost features. While he assessed many of the larger features in the White Mountains to be relict, the presence of active permafrost processes there suggests that similar conditions may exist in the Sierra Nevada, although patterned ground landforms can develop without permafrost (Ray et al., 1983).

These landforms are especially likely to occur on exposed plateaus and ridge tops where water collects, yet wind sweeps snow free, maintaining exposure of the ground surface to freezing air (Gleason, et al., 1986; Nelson et al., 1988; Kessler and Werner, 2003). The morphology and occurrence of features in PGA-Cr and PGA-NS categories on very high, rocky, and windswept locations at the extreme eastern

(dry) edge of the Sierran escarpment corroborate this. Other features (classed PGA-La) occur near lake margins where water tables are high yet exposed, and features of the BST-St type, which is similar to patterned ground, occurs along rivers. These environments have been noted as favorable for patterned ground formation in other regions (Mackay, 1980; Hallet et al., 1988; Hallet, 1990). Many of the features we mapped appeared to be active (criteria of Wilkerson, 1994) and potentially follow from the mechanics suggested by Kessler and Werner (2003) with form depending on initial slope, aspect, and edaphic conditions. Our categories of Patterned Ground differed somewhat from those described for the White

Mountains (Wilkerson, 1994) in that the Sierran features consisted of sorted rock throughout the feature with few or no fine-grained soils, whereas in the White Mountains many of the patterned ground features contained fines in the active surface matrix.

Inclusion in our classification of Mass Waste Features (MW) follows from our intent to recognize diverse yet related RIFs that might have unrecognized hydrologic significance in the Sierra Nevada. The sole category of Solifluction Fields (MWA-So) defines features that have been observed in the Sierra

Nevada but not studied as well as in the White Mountains (Wilkerson, 1994; Jones, 1993). Solifluction is a well-known periglacial process associated with high water content soils (Matsuoka, 2001; Ballantyne,

2002) and its role in transformation into patterned ground including nets and stripes has been studied

(Washburn, 1956; Gleason et al., 1986; Kessler and Werner, 2003). These features are thought to indicate the presence of seasonally or permanently saturated frozen ground sliding over ice or slick Millar and Westfall 24 bedrock. While the former seems unlikely in the Sierra Nevada, no studies have been conducted to investigate the subsurface conditions of these abundant slowly creeping alpine landforms in this range.

The geographic partitioning of our Sierra Nevadan Location Classes indicates their distinct environments. While most studies on rock glaciers and related features indicates that northerly orientations and elevations within the permafrost zone are common (e.g., Wahrhaftig and Cox, 1959;

Corte and Espizua, 1981; Burger, et al., 1999; Brenning, 2005), Johnson (1983) found no preferred orientations within valleys and that these features occupied diverse locations and elevations. The highest features in our classification were the Mass Wasting Solifluction Fields (MWA), followed by the Rock

Glacier/Rock Periglacier - Cirque features (RGC). The RGC class also had the most narrow range of northerly orientations, while other categories were more diverse, with the MWA class having features facing all main directions. Bradley et al (2006) found that elevations above 2600 m, north-facing aspect

(300-60°), and less than 2300 hours of direct sunlight per year were necessary conditions for existence of active rock glaciers. While our mapping emphasized the east side of the Sierra Nevada crest, both relict and active RIFs appear to be more dominant on the east than west side. Further, large, relict Pleistocene features are most common in the easternmost canyons of the eastslope. That is, those canyons whose heads are farthest east of the crest are more likely to contain Pleistocene RIFs than canyons that head near the crest. As there is no systematic difference in rock type along this gradient, the difference likely reflects a lower ice-to-rock volume in the increasing rainshadow of the eastern escarpment.

While we hope our field-based inventory and classification will benefit future research on these features, we acknowledge the limitations of our study. Because maps were made from field observations, based mostly on horizontal or angled views of features rather than aerial, inaccuracies of size and shape may exist. Some of the features have been confirmed for shape and extent by air photos, but not all. Air photos allow detection of the Rock Glacier/Rock Periglacier category only. Even the smaller of those features, such as the RGV types under avalanche chutes and cliffs, are often hidden in the shade in air photos, or don’t have adequate contrast for detection. The other condition states, Boulder Streams,

Patterned Ground, and Mass Waste Features, are difficult or impossible to detect from conventional air photos, and ground-mapping remains the best approach for their inventory.

Millar and Westfall 25

CLIMATIC RELATIONSHIPS

Our estimates of modern climate means from the PRISM model are the first assessments we know of for rock glaciers or related RIFs in temperate western North America. Modern climate relations for rock glaciers in other regions have been inferred from low-elevation weather stations (Humlum, 1998), based on assumptions of limiting climate requirements for permafrost (Frauenfelder, 2004; Aoyama, 2005), or estimated from mini-dataloggers installed in the local environment of a few specific features (Humlum,

1998; Krainer and Mostler, 2002; Aoyama, 2005). The PRISM model combines information from standard weather stations with additional relevant local information to output geographically seamless climate data for 4-km2 polygons (Daly et al., 1994). Using digital elevation models and local lapse rates from PRISM to adjust the polygon means for individual RIF sites, our resolution for estimating climate means is approximately 1.25 arcmin. Despite this resolution, our calculations may systematically underestimate local conditions of the RIFs. Although PRISM estimates elevation-related climate well, it does not incorporate local topographic conditions or aspect. Thus, reduced solar insolation, inversion effects, and north-facing aspects of many of the RIF cirque and related locations would not be included in the PRISM estimations.

Considerable attention has been paid to mean annual air temperatures (MAAT) required to support active rock glaciers and patterned ground processes, with the assumption by some researchers that permafrost necessarily underlies all features. Soil temperatures must persist below 0°C for at least two years to enable permafrost development; air temperatures to support this range from 0°C-5°C for discontinuous permafrost. In the Sierra Nevada, permafrost is not assumed to exist, and other mechanisms for ice persistence are suggested (Clark et al., 1994a). Clark et al. also found late summer temperatures slightly above 0°C from the silty sandy matrix in a 1-m pit in the terminus of a Sierran rock glacier, and silt-laden water at ~0°C from a spring on the front. None of our estimates from PRISM for

MAAT of the Location Classes was as low as 0°C, ranging instead from 0.57° to 2.17°C, although we also measured late summer water temperatures of 0°C from springs emanating at the base of several Sierra

RIFs (unpublished field survey). Our PRISM estimates compare to Brenning’s (2005) value of 0.5°C

MAAT of the main rock glacier zone of the Chilean Andes and discontinuous sites of active rock glaciers having MAAT of 4°C; comparable values were found in other Andean studies (Trombotto et al., 1997). Millar and Westfall 26

Similarly, in the Italian Alps, the mean elevation of the fronts of active rock glaciers was significantly lower than the -1°C isotherm, suggesting that either this temperature is not indicative of climate requirements for rock glacier formation or that the features studied were not in equilibrium with current climate (Baroni et al., 2003).

In the White Mountains, adjacent to the Sierra Nevada, permafrost has been documented by the presence of active patterned-ground processes (Wilkerson, 1994, 1995). At 3801 m in the White

Mountains, where these features exist, MAAT is -1.7°C with 455.6 mm mean annual precipitation (Powell and Kleiforth, 2001). At Niwot Ridge, Colorado, where active permafrost has been documented, MAAT is

-3.9°C at 3750 m, with 1020.8 mm precipitation (Ives, 1973).

Other direct measurements elsewhere indicated colder conditions related to rock glaciers, most of which have been interpreted to indicate permafrost. For instance, dataloggers placed at the base of the snow cover at an Austrian rock glacier recorded cool-season temperatures (Nov-May) between 0°C and -

10°C, whereas adjacent loggers on permafrost free areas did not record temperatures colder than 0°C

(Krainer and Mostler, 2002). Similarly, in the Japanese Alps, dataloggers recorded mean annual temperature at the base of the snow cover near rock glaciers less than -2°C, despite having mean annual temperature at ground surface above 0°C (Aoyama, 2005). In Spitsbergen, temperature measurements on and within a single rock glacier indicate mean annual ground temperatures less than 0°C (Humlum,

1998), with suggestions of a shallow permafrost depth. In a New Zealand inventory of rock glaciers, active forms were located within the climatic boundaries where the mean annual isotherm was -2°C or less for air temperature (Brazier et al., 1998).

Our estimates of mean differences between modern and Pleistocene temperatures (-4.3°C to -1.3°C) are similar to other estimates from rock glaciers and ice glaciers. Rather than using ELA or RILA to estimate climates, however, which are difficult or impossible with relict features, we estimated the difference in elevations of the base of active versus relict rock glaciers (mean 662 m). High variance in the elevations of the relict and modern features among watersheds, despite the fact that we used the same category of features, yielded a large range of estimates for the difference in climate. Similar variance in ELA levels of Recess Peak (late Pleistocene) advances in the Sierra Nevada was documented by Clark et al., (1994a) and in Japan (Aoyama, 2005) where local topographic control of Millar and Westfall 27 climate was implicated. Our estimates may be biased by misassignment of age, both of relict features as being LGM, and modern features as being active. Nonetheless, both methods we used gave similar results. In other regions estimates of late Holocene versus late Pleistocene temperatures from rock glaciers ranged from about -2°C (Swiss Alps, Barsch, 1996b; Frauenfelder and Kääb, 2000; Japan,

Aoyama, 2005) to -5.5°C (Chilean Andes, Brenning, 2005). In the case of the Japanese Alps, the mean difference between minimum elevations of active and relict rock glaciers (310 m) was about half what we estimated for the Sierra Nevada, and accounted for their temperature estimate (1.9°C) being about half of ours.

Conclusions

In this study we developed a regional classification of rock glaciers, rock periglaciers, and related rock- ice features derived from mapping 400 features in the central and southern Sierra Nevada, California.

The classification is based on morphology and location, is taxonomic in structure, and intentionally field- friendly to encourage further comprehensive mapping and intensive research on specific forms. The classification delineates specific forms that have been confounded by previous generalized terms and definitions, and includes a range of features that has not been included in rock glacier studies. With this we hope to draw attention to potentially significant yet overlooked hydrologic conditions of these landforms in semi-arid ranges such as the Sierra Nevada, including their contribution to groundwater storage and their role as distributed wetlands for alpine biodiversity within otherwise xeric, rockbound habitats.

Using the PRISM climate model, we estimated temperature and precipitation means for the six

Location Classes from the classification. While none of these indicated mean annual air temperatures lower than 0.5°C, the active nature of many features in the Sierra Nevada appears clear. The PRISM model may overestimate temperature relative to local topographic conditions of cirques and narrow, steep canyons, although it is possible that active RIFs are in disequilibrium with warming conditions of the 20th and 21st centuries. Based on mean difference in minimum elevations of active versus relict features, we estimate modern climates to be 1.3°C to 4.3°C warmer than Pleistocene late glacial conditions. Further research on the activity level of Sierra Nevada RIFs should enable estimations of Holocene climate changes as well. Millar and Westfall 28

Acknowledgments

We thank Andrew Fountain, Mike Dettinger, Lee Herrington, Matt Hoffman, Jessica Lundquist, Bob

Rice, and Forrest Wilkerson for helpful discussions and reviewing our manuscript; Chris Daly for consultations on the PRISM climate model; Doug Clark and Wally Woolfenden for critical discussions in the field; and Diane Delany for assistance with graphics.

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Table 1. Proposed taxonomy & nomenclature for rock-ice features in the Sierra Nevada.

Group: ROCK-ICE FEATURES

Condition Location Position Type Type Photo 1 State Class Type Locality Code

Rock Glacier/ Rock PeriGlacier (RG/RPG) Cirque Origin (RGC) Cirque Wall Lee Vining Cyn RGC-Cq Fig. 2a Valley Gibbs Cyn RGC-Va Fig. 2b Moraine Palisades, Middle Fork RGC-Mo Fig. 2c Pocket Robinson Cr, Tamarack RGC-Po Fig. 2d

Valley Wall Origin (RGV) Avalanche E Fk Rock Cr RGV-Av Fig. 3a Talus Cone Little Walker, Poison RGV-Ta Fig. 3b Scree Slope Lundy, Lake Cyn RGV- Sc Fig. 3c Cliff Slope E FK Rock Cr, Francis RGV-Cl Fig. 3d

Boulder Stream (BS) Scree Slopes (BSC) Avalanche Green Cr, Dunderberg BSC-Av Fig. 4a Talus Cone Gibbs Cyn BSC-Ta Fig. 4b Scree Slope Parker Pass, Kuna Crest BSC-Sc Fig. 4c Snowfield Apron Palisades, S Fork BSC-Sn Fig. 4d Cliff Little Walker Cr, Poison BSC-Cl Fig. 4e

Stream Courses (BST) Stream Course Lee Vining Cyn, Glacier BST-St Fig. 4f

Patterned Ground (PG) Alpine Flats & Slopes (PGA) Lake Margin E Frk Rock Cr PGA-La Fig. 5a Circle Parker Cyn, Koip Pass PGA-Cr Fig. 5b Net, Stripe Little Walker, Poison PGA-NS Fig. 5c

Mass Waste Features (MW) Alpine Slopes (MWA) Solifluction Field Virginia Cyn MWA-So Fig. 5d

1 Locations of type localities are given in Appendix 1. Millar and Westfall 41

Table 2. Summary of Sierra Nevada rock-ice features by taxonomic groups.

Mean Mean Group Condition Location Class Number Mean Elev Elev Elev Active Active; Active; Active; Active; Mean Shape Low High Mean Mean State Class Code Mapped Elev Range (m) (m) % Mean Elev Elev Elev Size Long Equal Wide Elev Range Low High (m) (m) (m) (m) (m) (m) (ha) % % % Rock-Ice 2225- 2673- Features All All 395 3295 3932 3205 3356 75 3333 3932 3253 3385 15 33 41 26

Rock Glacier/ Rock 2225- 2673- PeriGlacier Cirque RGC 169 3324 3932 3243 3405 67 3390 3901 3306 3448 20 40 40 20

2804- 2941- Valley Wall RGV 96 3243 3840 3201 3285 69 3292 3840 3205 3337 3 12 27 61

Boulder Scree 2743- 2743- Stream Slopes BSC 71 3253 3780 3189 3317 89 3256 3780 3157 3317 4.8 39 54 7

Stream 2804- 2804- Course BST 22 3228 3597 3201 3256 100 3228 3597 3201 3256 2.4 91 9 0

Alpine 3066- 3166- Patterned Flats PGA 15 3273 3510 3268 3278 73 3322 3510 3276 3285 1.1 33 47 20 Ground & Slopes

Alpine 3109- 3109- Mass Waste Slopes MWA 22 3509 3932 3439 3578 100 3509 3932 3439 3578 15 0 91 9

Millar and Westfall 42

Table 3. Canonical correlations from discriminate analysis among nine climate variables from the PRISM

climate model and correlations of the first three canonical vectors (CV) with the climate variables.

Annual January July Annual January July Annual January July T T precip precip precip T max T max max T min T min min Annual precip 1.000 January precip 0.927 1.000 July precip -0.060 -0.183 1.000 Ann T max 0.028 0.168 0.187 1.000 Jan T max -0.069 0.003 0.029 0.877 1.000 July T max 0.033 0.182 0.228 0.975 0.772 1.000 Annual T max -0.139 -0.083 0.516 0.786 0.574 0.810 1.000 January T max -0.109 -0.032 0.129 0.809 0.780 0.760 0.825 1.000 July T min -0.201 -0.199 0.668 0.595 0.347 0.659 0.941 0.622 1.000 CV 1 -0.095 -0.037 -0.393 0.373 0.593 0.347 -0.068 0.211 0.178 CV 2 -0.311 -0.201 0.625 0.714 0.529 0.715 0.735 0.436 0.737 CV 3 0.118 0.077 0.507 -0.280 -0.311 0.195 -0.155 -0.346 0.015

Millar and Westfall 43

Table 4. Summary of ten mean climate values for six R-I Location Classes derived from the 4km2 PRISM model.

Active features only, PRISM values adjusted for elevation.

Location N Annual Annual Annual January January July July Annual January July T T Class1 Temp T min T max T min T max min max Precip Precip Precip ˚C ˚C ˚C ˚C ˚C ˚C ˚C mm mm mm MWA 22 0.57 -5.70 6.84 -12.55 -1.26 3.46 17.93 1126 198 24 RGC 113 0.90 -5.65 7.45 -12.01 -0.54 3.27 18.46 1050 184 19 RGV 67 1.01 -5.84 7.86 -11.98 -0.03 2.96 19.00 1055 187 18 BSC 63 1.72 -4.90 8.34 -11.71 -0.08 4.30 19.61 1004 178 26 PGA 8 1.95 -4.97 8.87 -11.37 0.40 3.73 20.16 1027 189 16 BST 21 2.17 -4.77 9.11 -11.37 0.60 4.14 20.47 1019 181 21

1 See Table 1 for Location Class codes

Millar and Westfall 44

Table 5. Difference in temperatures estimated for modern versus Pleistocene climates based on lower elevations of paired active (A) versus relict Pleistocene (P) rock glaciers within watersheds. All features are classed as RGC-Va (P) or RGC-Cq and RGC-Va (A). Annual temperature (T ann) differences calculated using standard lapse rate (-0.0065C/m); annual maximum and minimum temperatures (T max, T min, respectively) and January and July maximum and minimum temperatures (Jan T max, July T max, Jan T min, and Jul T min, respectively) calculated from PRISM model, adjusted for elevation. In the latter case, lapse rates varied by watershed (see text). In one case (Cottonwood and Center Basin), features are not within a watershed, but closest available set is used.

Mean Diff Watershed Age Elev Latitude Longitude in Std Lapse PRISM-Estimated Diff in Temperature Diff in T (m) Elev A - P ann A - P (˚C) Jan T Jul T T Jan T Jul T (m) A - P ( °C ) T max max max min min min

Tamarack P 2747 38.1442 119.3160 Tamarack A 3372 38.1027 119.3193 625 -4.1 -0.3 0.2 -0.7 -0.3 -0.2 -0.2 Dunderberg P 2637 38.1033 119.2485 Dunderberg A 3422 38.0692 119.2730 785 -5.1 -3.0 -2.6 -3.4 -0.8 -0.6 -0.7 Deer Crk P 2526 38.0262 119.2165 Deer Crk A 3166 38.0017 119.2237 640 -4.2 -5.6 -4.3 -6.8 -1.1 -1.0 -1.0 Dechambeau P 2690 38.0159 119.1889 Dechambeau A 3416 37.9931 119.2192 726 -4.7 -2.1 -1.2 -2.1 -0.2 0.0 -0.1 1 Warren P 3037 37.9892 119.1853 Warren A 3351 37.9782 119.2126 314 -2.0 -2.8 -2.2 -3.5 -0.4 -0.6 -0.3 LV Cyn Dana P 2505 37.9415 119.2125 LV Cyn Dana A 3484 37.9023 119.2168 979 -6.4 -4.7 -2.9 -4.7 -2.0 -1.4 -1.7 Gibbs Cyn P 2615 37.9138 119.1578 Gibbs Cyn A 3202 37.8971 119.2012 587 -3.8 -2.6 -2.0 -3.9 -0.6 -1.2 -0.6 Bloody Cyn Clot P 2613 37.8664 119.1735 1 Bloody Cyn P 3086 37.8581 119.1939 Bloody Cyn A 3314 37.8486 119.1961 Bloody Cyn A 3523 37.8454 119.1889 569 -3.7 -3.9 -2.2 -4.6 -2.4 -2.2 -2.1 Bloody Cyn 1 Gibbs P 3123 37.8625 119.2002 Bloody Cyn Gibbs A 3665 37.8787 119.2073 542 -3.5 -1.7 -1.7 -2.0 -0.5 -0.9 -0.6 Parker Lk P 2594 37.8326 119.1403 Parker Kuna A 3652 37.8212 119.2095 1058 -6.9 -5.6 -4.1 -6.1 -3.0 -3.4 -2.6 Hilton Cr P 2264 37.5611 118.7666 Hilton Cr A 3454 37.4606 118.7653 1190 -7.7 -8.0 -6.5 -8.5 -4.7 -5.9 -4.1

Millar and Westfall 45

Mean Diff Watershed Age Elev Latitude Longitude in Std Lapse PRISM-Estimated Diff in Temperature Diff in T (m) Elev A - P ann A -P (˚C) Jan T Jul T T Jan T Jul T (m) A - P ( °C ) T max max max min min min 1 Francis Cr P 3169 37.4428 118.7141 Francis Cr A 3673 37.4160 118.7277 504 -3.3 -8.1 -6.1 -9.7 -4.8 -4.2 -5.0 Bishop Cr N Fk P 2858 37.2275 118.6282 Bishop Cr N Fk A 3490 37.2374 118.6364 632 -4.1 -1.5 -0.9 -1.8 -0.3 -0.3 0.1 Poison Cr Walker P 2615 38.2902 119.4771 Poison Cr Walker A 3055 38.2741 119.4866 400 -2.6 -1.6 -1.2 -2.1 -1.2 -0.9 -0.8 Cottonwood Cr P 3121 36.4686 118.1918 Center Basin A 3507 36.7262 118.3616 386 -2.5 -0.4 -0.9 0.1 -2.5 -4.7 -0.6

AVERAGE 662 -4.3 -3.5 -2.6 -4.0 -1.7 -1.8 -1.3

1 Lower elevation truncated by mainstem valley-glacier erosion or range-front faulting.

Millar and Westfall 46

FIGURES

Fig. 1. Map of the study area, Central Sierra Nevada, California, USA. Rock-Ice features mapped and classified in this paper were between Sonora and Cottonwood Passes, and primarily east of the Sierra

Crest.

Fig. 2. Type locality of RGC Position Types. A RGC-Cq; Lower Lee Vining Canyon – Dana Cliffs (likely inactive). B. RGC-Va; Gibbs Canyon. C. RGC-Mo; Palisades, Middle Fork Glacier. D. RGC-Po;

Robinson Cr – Tamarack Cyn (relict).

Fig. 3. Type locality of RGV Position Types. A. RGV-Av; East Fork Rock Creek. B. RGV-Ta; Little

Walker Cyn, Emma Lk. C. RGV-Sc; Lundy Cyn – Lake Cyn. D. RGV-Cl; East Fork Rock Creek, Francis

Creek.

Fig. 4. Type locality of BSC Position Types. A. BSC-Av; Green Creek – Mt Dunderberg. B. BSC-Ta;

Gibbs Cyn. C. BSC-Sc; Kuna Crest, Lk Helen. D. BSC-Sn; S Fk Bishop Creek. E. BSC-Cl; Little Walker

Cyn – Emma Lk. F. BST-St; Glacier Cyn – Lee Vining Cyn.

Fig. 5. Type locality of PGA-Position Types. A. PGA-La; East Fk Rock Creek. B. PGA-Cr; Parker Pk,

Koip Pass. C. PGA-NS; Little Walker Cyn – Emma Pk. D. MWA-So; Virginia Cr – Mt. Olsen.

Fig. 6. Slope aspects summarized for six Location Classes of Rock-Ice Features in the Sierra Nevada.

Direction of the wind-rose arms indicates cardinal slope aspects (N up); length of the arms indicates the proportion of features found in that aspect of the total in the Class. Sample numbers vary by Location

Class (see Table 2).

Fig. 7. Canonical vector plot for the first two canonical vectors (Can Vector) from discriminant analysis of six Rock-Ice Feature Location Classes and ten PRISM climate variables. Labels indicate the mean of the Millar and Westfall 47 distribution for each Location Class (A = BSC; B = BST; C = MWA; D = RGC; E = RGV; F [largest ellipse]

= PGA); ellipses include 95% of the data points for each group, axes are canonical scores. Can Vector 1 is correlated with January maximum temperature; Can Vector 2 is correlated with January maximum temperature, July minimum temperature, annual minimum temperature, and July precipitation. See Table

1 for Location Class codes. Figure 1

Figure 2 Figure 3

Figure 4

Figure 5 Figure 6 Figure 7

Appendix 1. Rock-Ice Features Mapped in the Sierra Nevada, California. Type Localities are indicated.

Watershed Latitude Longitude Position Activity2 Age3 Mean Elev Elev Aspect Shape4 Size5 N W Type1 Elev High Low (deg) (m) (m) (m)

Bishop Cr-NorthFkLk 37.2299 -118.6219 RGC-Va R P-R 3211 3597 2825 140 1 4 Bishop Cr-NorthFkLk 37.2297 -118.6529 RGV-Cl A H 3301 3322 3280 0 0 2 Bishop Cr-NorthFkLk 37.2370 -118.6289 RGV-Sc A H 3368 3444 3292 140 1 3 Bishop Cr-NorthFkLk 37.2314 -118.6247 RGV-Sc R H, P 3185 3200 3170 140 1 3 Bishop Cr-NorthFkLk 37.2223 -118.6015 RGV-Ta R P 2880 2957 2804 330 0 2 Bishop Cr-NorthFkLk 37.2262 -118.5982 RGV-Ta R P 2858 2896 2819 335 0 2 BloodyCyn 37.8562 -119.1997 BSC-Ta A H 3109 3170 3048 0 0.5 1 BloodyCyn 37.8677 -119.2057 BSC-Ta A H 3170 3292 3048 140 1 2 BloodyCyn 37.8544 -119.1960 BST-St A H 3178 3231 3124 5 1 1 BloodyCyn 37.8514 -119.1968 BST-St A H 3231 3292 3170 5 1 1 BloodyCyn 37.8784 -119.2047 RGC-Cq A H 3673 3719 3627 110 0.5 3 BloodyCyn 37.8531 -119.1962 RGC-Mo R P 3277 3292 3261 5 0.5 1 BloodyCyn 37.8677 -119.2057 RGC-Mo R P 3353 3658 3048 160 1 3 BloodyCyn 37.8482 -119.1960 RGC-Va A H 3353 3414 3292 5 0.5 3 BloodyCyn 37.8462 -119.1893 RGC-Va A H 3520 3627 3414 320 0.5 3 BloodyCyn 37.8462 -119.1893 RGC-Va R P 3520 3627 3414 320 0.5 3 BloodyCyn 37.8490 -119.1851 RGC-Va R P 3231 3292 3170 50 0.5 3 BloodyCyn 37.8663 -119.1695 RGC-Va R P 2850 3109 2591 15-30 1 4 BloodyCyn 37.8737 -119.2023 RGC-Va R P 3597 3658 3536 140 1 3 BloodyCyn 37.8711 -119.1930 RGV-Av A H 3353 3658 3048 90 1 2 BloodyCyn 37.8702 -119.1936 RGV-Av A H 3353 3658 3048 90 1 2 BloodyCyn 37.8763 -119.1973 RGV-Av A H 3581 3658 3505 90 1 2 BloodyCyn 37.8609 -119.1884 RGV-Cl A H 2964 2987 2941 350 0 1 BloodyCyn 37.8564 -119.1997 RGV-Cl A H 3078 3109 3048 0 0.5 1 BloodyCyn 37.8562 -119.1941 RGV-Cl A H 3123 3155 3091 340 0.5 2 BloodyCyn 37.8541 -119.1923 RGV-Sc A H 3240 3261 3219 320 0 1 Buckeye-EagleCrEaglePk 38.1821 -119.4076 MWA-So A H 3444 3536 3353 45 0.5 2 Buckeye-EagleCrEaglePk 38.1742 -119.4023 RGC-Cq A H 3269 3292 3246 150 0.5 2 Buckeye-EagleCrEaglePk 38.1774 -119.4014 RGC-Cq A H 3353 3414 3292 130 0.5 2 ColiseumMt, DivisionCr 36.9038 -118.3580 RGC-Va A H 3307 3536 3078 70-10 1 4

1 ConvictCyn 37.5727 -118.8597 RGC-Cq A H 2865 2926 2804 350 1 2 ConvictCyn 37.5146 -118.8710 RGC-Mo A H 3475 3536 3414 0 0 2 ConvictCyn 37.5114 -118.8664 RGC-Mo A H 3490 3566 3414 0 0 2 ConvictCyn 37.5458 -118.8838 RGC-Mo R P-R 3200 3246 3155 150 0 1 ConvictCyn 37.5244 -118.8847 RGC-Va A H 3376 3459 3292 350-0 0.5 3 ConvictCyn 37.5275 -118.8951 RGC-Va A H 3475 3536 3414 45 0.5 3 ConvictCyn 37.5735 -118.8433 RGC-Va R P 2774 3048 2499 0-350 1 4 ConvictCyn 37.5455 -118.8853 RGV-Sc A H 3254 3261 3246 140 0 1 Cottonwood Crk 36.4845 -118.2167 RGC-Va R P 3455 3741 3168 90-110 1 4 Deer Cr (Mammoth Crest) 37.5594 -118.9806 BSC-Sc R P 3238 3399 3077 248 1 2 Deer Cr (Mammoth Crest) 37.5578 -118.9839 BST-St A H 3327 3338 3316 305 1 2 Deer Cr (Mammoth Crest) 37.5571 -118.9814 BST-St A H 3370 3362 3379 330 1 1 Deer Cr (Mammoth Crest) 37.5586 -118.9814 PGA-NS A H 3340 3340 3340 248 0.5 1 Deer Cr (Mammoth Crest) 37.5614 -118.9789 PGA-NS R H 3414 3420 3408 160 1 2 Deer Cr (Mammoth Crest) 37.5552 -118.9824 RGC-Va A H 3385 3429 3341 3 1 3 DuckLk-FishCr-LongCyn 37.4752 -119.0150 RGV-Av A H 3289 3316 3261 42 0.5 2 DuckLk-FishCr-LongCyn 37.5440 -118.9617 RGV-Cl A H 3246 3292 3200 340 1 3 DuckLk-FishCr-LongCyn 37.5486 -118.9501 RGV-Cl A H 3246 3292 3200 310 0 2 DuckLk-FishCr-LongCyn 37.5532 -118.9335 RGV-Cl A H 3387 3451 3322 270 0 1 DuckLk-FishCr-LongCyn 37.5475 -118.9477 RGV-Cl A H 3566 3597 3536 340 0 1 DuckLk-FishCr-LongCyn 37.4558 -118.9933 RGV-Sc A H 3307 3322 3292 12 0.5 2 DuckLk-FishCr-LongCyn 37.5595 -118.9467 RGV-Ta A H 3475 3505 3444 270 1 1 EastFkRockCr-EastFork 37.4246 -118.7041 BSC-Sc A H 3362 3414 3310 25-35 1 2 EastFkRockCr-EastFork 37.4246 -118.7041 BST-St A H 3328 3353 3304 28 1 2 EastFkRockCr-EastFork 37.4130 -118.7021 MWA-So A H 3856 3932 3780 290 0.5 2 EastFkRockCr-EastFork 37.4324 -118.7045 RGC-Po R P 3321 3399 3243 50 0.5 3 EastFkRockCr-EastFork 37.4078 -118.7119 RGC-Va A H 3658 3780 3536 25 1 3 EastFkRockCr-EastFork 37.4094 -118.7165 RGC-Va A H 3703 3780 3627 55 1 3 EastFkRockCr-EastFork 37.4175 -118.7125 RGC-Va R R, P 3633 3731 3536 60-90 1 4 EastFkRockCr-EastFork 37.4186 -118.7030 RGV-Av A H 3353 3414 3292 275 1 2 EastFkRockCr-EastFork 37.4252 -118.6993 RGV-Av A H 3367 3411 3322 300 0 1 EastFkRockCr-EastFork 37.4261 -118.6983 RGV-Cl A H 3406 3459 3353 320 0 1 EastFkRockCr-EastFork 37.4272 -118.6958 RGV-Sc A H 3406 3429 3383 325 0 1 EastFkRockCr-EastFork 37.4322 -118.6925 RGV-Sc A H 3406 3429 3383 320 0 1 EastFkRockCr-EastFork 37.4384 -118.6922 RGV-Sc R P-R 3345 3399 3292 275 0 2 EastFkRockCr-EastFork 37.4223 -118.7015 RGV-Ta A H 3429 3475 3383 290 0 1 EastFkRockCr-EastFork TYPE PGA-LA 37.4108 -118.7076 PGA-La A H 3293 3293 3292 0 0 2

2 EastFkRockCr-EastFork TYPE RGV-AV 37.4287 -118.6950 RGV-Av A H 3353 3383 3322 300 0 1 EastFkRockCr-EastFork TYPE RGV-TA 37.4311 -118.6960 RGV-Ta R P-R 3360 3383 3338 320 0 1 EastFkRockCr-Francis Cyn 37.4215 -118.7191 MWA-So A H 3810 3901 3719 350 0.5 3 EastFkRockCr-Francis Cyn 37.4147 -118.7276 RGC-Cq A H 3764 3810 3719 0-20 0.5 3 EastFkRockCr-Francis Cyn 37.4284 -118.7255 RGC-Va R P-R 3597 3780 3414 30 1 4 EastFkRockCr-Francis Cyn 37.4385 -118.7185 RGC-Va R P 3566 3840 3292 30 1 4 EastFkRockCr-Francis Cyn 37.4207 -118.7230 RGV-Av A H 3688 3719 3658 345 0 1 EastFkRockCr-Francis Cyn 37.4219 -118.7321 RGV-Av A H 3749 3840 3658 30 0.5 3 EastFkRockCr-Francis Cyn 37.4313 -118.7163 RGV-Sc A H 3322 3353 3292 307 0 2 EastFkRockCr-Francis Cyn 37.4319 -118.7172 RGV-Sc A H 3338 3383 3292 340 0 2 EastFkRockCr-Francis Cyn 37.4268 -118.7206 RGV-Sc A H 3399 3444 3353 18 0 1 EastFkRockCr-Francis Cyn 37.4244 -118.7225 RGV-Sc A H 3399 3444 3353 18 0 1 EastFkRockCr-Francis Cyn 37.4290 -118.7184 RGV-Sc A H 3414 3429 3399 308 0 2 EastFkRockCr-Francis Cyn 37.4323 -118.7179 RGV-Ta R P 3429 3429 3429 330 0 2 EastFkRockCr-Francis Cyn TYPE RGC-CL 37.4339 -118.7135 RGV-Cl A H 3353 3414 3292 320 1 3 FrenchCy-WsideFrenchLk 37.3038 -118.7012 RGC-Cq A H 3714 3770 3658 350 0 1 Gibbs 37.9114 -119.1837 BSC-Sc A H 3612 3780 3444 5 0.5 4 Gibbs 37.9012 -119.1919 BSC-Ta A H 3200 3353 3048 170 1 2 Gibbs 37.9022 -119.1961 BSC-Ta A H 3267 3414 3121 170 1 2 Gibbs 37.8988 -119.2018 BSC-Ta A H 3307 3414 3200 160-180 0.5 3 Gibbs 37.9055 -119.1666 RGC-Va R P 2713 2896 2530 60 1 4 Gibbs 37.9044 -119.1818 RGC-Va R P 2789 3018 2560 68 1 4 Gibbs 37.8975 -119.1897 RGV-Cl A H 3101 3139 3063 23 0.5 1 Gibbs 37.8961 -119.1946 RGV-Ta A H 3139 3170 3109 15 0.5 3 Gibbs TYPE BSC-TA 37.9015 -119.1938 BSC-Ta A H 3223 3353 3094 170 1 2 Gibbs; TYPE RGC-VA 37.8948 -119.2043 RGC-Va A H 3292 3414 3170 355-358 1 4 Glacier Cyn-LV Cyn 37.9121 -119.2311 BSC-Sc A H 3322 3353 3292 0 1 1 Glacier Cyn-LV Cyn 37.9079 -119.2105 BSC-Sc A H 3627 3719 3536 330 0.5 3 Glacier Cyn-LV Cyn 37.9148 -119.2431 BSC-Sn R P 3152 3231 3072 300 0.5 2 Glacier Cyn-LV Cyn 37.9222 -119.2248 MWA-So A H 3574 3734 3414 325-340 0.5 3 Glacier Cyn-LV Cyn 37.9149 -119.2314 PGA-NS A H 3322 3353 3292 300 1 1 Glacier Cyn-LV Cyn 37.9017 -119.2168 RGC-Mo A H 3496 3505 3487 18 0 1 Glacier Cyn-LV Cyn 37.9090 -119.2245 RGV-Cl A H 3429 3444 3414 50 0 1 Glacier Cyn-LV Cyn 37.9107 -119.2198 RGV-Sc R P 3456 3493 3420 230 0 1 Glacier Cyn-LV Cyn 37.9075 -119.2180 RGV-Sc R P 3456 3493 3420 230 0 1 Glacier Cyn-LV Cyn 37.9170 -119.2142 SFSA A H 3520 3566 3475 320 0.5 3 Glacier Cyn-LV Cyn TYPE BST-ST 37.9112 -119.2254 BST-St A H 3322 3353 3292 300 1 1

3 GreenCr-DunderbergCr 38.0665 -119.2704 BSC-Av A H 3545 3658 3432 18 1 2 GreenCr-DunderbergCr 38.0682 -119.2666 BSC-Sc A H 3543 3658 3429 11 1 2 GreenCr-DunderbergCr 38.0676 -119.2669 BSC-Sc A H 3549 3655 3444 12 1 2 GreenCr-DunderbergCr 38.0774 -119.2649 BSC-Sn A H 3232 3240 3225 60 0.5 2 GreenCr-DunderbergCr 38.0743 -119.2643 BSC-Sn A H 3245 3249 3240 63 0.5 2 GreenCr-DunderbergCr 38.0701 -119.2623 BST-St A H 3178 3185 3170 5 1 1 GreenCr-DunderbergCr 38.0740 -119.2626 BST-St A H 3368 3505 3231 5 1 1 GreenCr-DunderbergCr 38.0692 -119.2741 MWA-So A H 3459 3505 3414 32 0.5 3 GreenCr-DunderbergCr 38.0764 -119.2617 PGA-La A H 3167 3168 3166 3 0.5 1 GreenCr-DunderbergCr 38.0776 -119.2643 PGA-NS A H 3222 3225 3219 65 1 1 GreenCr-DunderbergCr 38.0732 -119.2676 RGC-Mo R P 3368 3383 3353 3 1 3 GreenCr-DunderbergCr 38.0703 -119.2727 RGC-Mo R P 3429 3444 3414 38 0 2 GreenCr-DunderbergCr 38.0879 -119.2493 RGC-Va R P 3109 3536 2682 0-30 1 4 GreenCr-DunderbergCr TYPE BSC-AV 38.0679 -119.2680 BSC-Av A H 3519 3603 3435 10 1 2 GreenCr-EastFk 38.0705 -119.2825 RGC-Cq A H 3089 3130 3048 330 1 2 GreenCr-EastFk 38.0579 -119.2879 RGC-Cq A H 3185 3231 3139 350 0.5 2 GreenCr-WestFk 38.0898 -119.3241 BSC-Sc A H 3101 3124 3078 3 0.5 2 GreenCr-WestFk 38.0914 -119.3406 RGC-Cq A H 3414 3444 3383 90 0.5 2 greenCr-WestFk 37.9853 -119.3148 RGC-Mo A H 3426 3475 3377 90 0.5 1 GreenCr-WestFk 38.0880 -119.3184 RGC-Va A H 3124 3139 3109 350-0 0 1 GreenCr-WestFk 38.0875 -119.3207 RGC-Va A H 3155 3170 3139 350-0 0 1 GreenCr-WestFk 38.0876 -119.3426 RGC-Va A H 3437 3475 3399 90 0 1 GreenCr-WestFk 38.0898 -119.3201 RGV-Ta A H 3155 3170 3139 350-0 0.5 1 HiltonCr 37.5299 -118.7656 RGC-Va R P 2637 3048 2225 0 1 4 HiltonCr 37.4969 -118.7517 RGV-Sc R P 3155 3322 2987 280 0 3 Little Walker; Poison Cr TYPE BSC-CL 38.2798 -119.4837 BSC-Cl A H 2861 2880 2841 15 0.5 2 Little Walker; Poison Cr 38.2783 -119.4817 BSC-Cl A H 2931 2943 2920 340 0.5 1 Little Walker; Poison Cr 38.2825 -119.4816 BST-St A H 2812 2819 2804 35 1 2 Little Walker; Poison Cr TYPE PGA-NS 38.2767 -119.4771 PGA-NS R R,P? 3185 3200 3170 200 1 1 Little Walker; Poison Cr 38.2766 -119.4820 RGC-Va A H 2838 3002 2673 330 0 2 Little Walker; Poison Cr 38.2836 -119.4825 RGC-Va R P 2764 2821 2708 12 1 2 Little Walker; Poison Cr 38.2796 -119.4814 RGV-Sc R H,P 2899 2911 2886 350 0 2 Little Walker; Poison Cr 38.2796 -119.4814 RGV-Ta R H,P 2900 2912 2887 350 0 2 Little Walker; Poison Cr TYPE RGV-TA 38.2784 -119.4817 BSC-Ta A H 2935 2944 2926 340 0.5 2 Lower LVC - Ellery 37.9297 -119.2298 BSC-Sc A H 3109 3170 3048 1 1 2 Lower LVC - Ellery 37.9284 -119.2338 RGC-Cq A H 3261 3292 3231 12 0 3 Lower LVC - Ellery 37.9275 -119.2287 RGC-Va A H 3231 3292 3170 350 1 2

4 Lower LVC - Ellery 37.9336 -119.2284 RGV-Sc R P 2967 2996 2938 305 0 2 Lower LVC - Warren 37.9691 -119.2459 BSC-Cl A H 3002 3018 2987 210 0 2 Lower LVC - Warren 37.9721 -119.2525 BSC-Cl A H 3109 3121 3097 111 0 1 Lower LVC - Warren 37.9704 -119.2517 BSC-Sc A H 3117 3170 3063 47 0.5 3 Lower LVC - Warren 37.9748 -119.2501 BSC-Sc A H 3147 3155 3139 208 0.5 2 Lower LVC - Warren 37.9755 -119.2566 BSC-Sc A H 3216 3292 3139 101 1 3 Lower LVC - Warren 37.9724 -119.2494 BSC-Sn A H 3075 3078 3072 192 1 1 Lower LVC - Warren 37.9731 -119.2481 BSC-Sn A H 3112 3115 3110 236 0.5 1 Lower LVC - Warren 37.9749 -119.2502 MWA-So A H 3124 3139 3109 210 0.5 1 Lower LVC - Warren 37.9771 -119.2550 RGC-Cq A H 3200 3231 3170 122 0.5 2 Lower LVC - Warren 37.9732 -119.2504 RGC-Mo R P 3095 3118 3072 152 0.5 3 Lower LVC - Warren 37.9769 -119.2539 RGC-Mo R P 3171 3179 3164 142 0 1 Lower LVC - Warren 37.9705 -119.2504 RGC-Mo R P 3068 3060 3075 53 0 1 Lower LVC - Warren 37.9761 -119.2506 RGV-Sc A H 3161 3165 3156 233 0 1 LowerLVC-DanaCliffs 37.9124 -119.1849 BSC-Cl R P 3033 3170 2896 86-95 0.5 4 LowerLVC-DanaCliffs 37.9154 -119.2067 RGC-Cq A H 3338 3383 3292 55 0.5 2 LowerLVC-DanaCliffs 37.9110 -119.2012 RGC-Mo R P 3467 3505 3429 5 0 2 LowerLVC-DanaCliffs 37.9086 -119.2026 RGC-Va R P 3616 3696 3536 12 0.5 4 LowerLVC-DanaCliffs 37.9212 -119.1878 RGC-Va R P 2731 2957 2505 28 1 4 LowerLVC-DanaCliffs 37.9212 -119.1986 RGC-Va R P 2783 3200 2365 18-79 1 4 LowerLVC-DanaCliffs 37.9255 -119.2023 RGC-Va R P 2797 3231 2362 75 1 4 LowerLVC-DanaCliffs; RGC-CQ TYPE 37.9065 -119.2057 RGC-Cq A H 3606 3639 3572 23 0 3 LowerLVC-KaroKyn 37.9345 -119.2169 RGC-Cq R P 3052 3060 3044 85 0 2 LowerLVC-KaroKyn 37.9294 -119.2140 RGC-Cq R P 3208 3222 3194 315 1 3 LowerLVC-KaroKyn 37.9317 -119.2159 RGC-Va A H 3083 3094 3071 5 0.5 2 LowerLVC-KaroKyn 37.9283 -119.2169 RGC-Va A H 3191 3197 3185 3 1 3 LowerLVC-KaroKyn 37.9273 -119.2159 RGC-Va A H 3209 3216 3203 360 1 3 LowerLVC-KaroKyn 37.9358 -119.2131 RGC-Va R P 2903 2908 2899 2 0.5 2 LowerLVC-KaroKyn 37.9338 -119.2148 RGC-Va R P 2996 3005 2987 5 0.5 2 LowerLVC-KaroKyn 37.9309 -119.2159 RGC-Va R P 3092 3267 2917 5 1 4 Lundy-BurroCarnelian 38.0352 -119.2770 MWA-So A H 3459 3505 3414 110 0.5 2 Lundy-BurroCarnelian 38.0254 -119.2989 RGC-Cq A H 3499 3584 3414 43 1 2 Lundy-BurroCarnelian 38.0289 -119.3032 RGC-Cq A H 3505 3597 3414 55 0.5 2 Lundy-BurroCarnelian 38.0319 -119.2923 RGC-Mo R P 3353 3292 3414 55 1 3 Lundy-BurroCarnelian 38.0296 -119.2891 RGV-Cl A H 3328 3414 3243 18 0.5 2 LundyCynUpper-20LksNPk 37.9868 -119.3100 BSC-Sc A H 3170 3200 3139 2 1 2

5 LundyCynUpper-20LksNPk 37.9882 -119.3085 BSC-Sc A H 3158 3167 3149 2 1 2 LundyCynUpper-20LksNPk 37.9972 -119.2854 BSC-Sc A,R H 3269 3368 3170 260 0.5 2 LundyCynUpper-20LksNPk 38.0022 -119.2903 BSC-Sn A H 3143 3170 3117 320 0.5 1 LundyCynUpper-20LksNPk 38.0022 -119.2903 BST-St A H 3143 3170 3117 320 0.5 1 LundyCynUpper-20LksNPk 37.9972 -119.2854 MWA-So A H 3208 3246 3170 260 0.5 1 LundyCynUpper-20LksNPk 38.0020 -119.3084 RGC-Cq A H 3443 3453 3432 150 0.5 2 LundyCynUpper-20LksNPk 37.9995 -119.3088 RGC-Cq R P 3338 3383 3292 170 0.5 2 LundyCynUpper-20LksNPk 37.9839 -119.3120 RGC-Mo A H 3261 3322 3200 34 1 2 LundyCynUpper-20LksNPk 37.9898 -119.3154 RGC-Mo A H 3383 3444 3322 20 0.5 2 LundyCynUpper-20LksNPk 37.9868 -119.3102 RGV-Sc R P 3178 3185 3170 2 0.5 2 Lundy-Dechambeau 38.0104 -119.1971 RGC-Va R P 2768 3097 2438 30 1 4 Lundy-Deer Cr 38.0163 -119.2170 BST-St A H 2880 2896 2865 5 1 2 Lundy-Deer Cr 38.0113 -119.2197 BST-St A H 2911 2926 2896 5 1 2 Lundy-Deer Cr 37.9978 -119.2199 RGC-Cq A,R H 3353 3414 3292 2 0.5 3 Lundy-Deer Cr 38.0180 -119.2166 RGC-Va R P 2865 3109 2621 8 1 4 Lundy-Deer Cr 38.0050 -119.2208 RGV-Sc A H 3109 3170 3048 8 0.5 3 Lundy-Lk Cyn 37.9967 -119.2519 BSC-Sn A H 3030 3109 2950 90 0.5 2 Lundy-Lk Cyn 37.9883 -119.2392 MWA-So A H 3490 3520 3459 20 0 1 Lundy-Lk Cyn 37.9835 -119.2546 RGC-Cq A H 3085 3121 3048 45 0.5 2 Lundy-Lk Cyn 37.9887 -119.2572 RGC-Cq A H 3086 3124 3048 30 0.5 2 Lundy-Lk Cyn 37.9927 -119.2581 RGC-Cq A H 3147 3170 3124 70 0 1 Lundy-Lk Cyn 37.9918 -119.2386 RGC-Cq A H 3406 3459 3353 315 0.5 2 Lundy-Lk Cyn 37.9891 -119.2399 RGC-Cq A H 3490 3520 3459 20 0 1 Lundy-Lk Cyn 37.9940 -119.2390 RGC-Va A, R H 3246 3292 3200 335 0.5 2 Lundy-Lk Cyn 37.9966 -119.2377 RGC-Va R H, P 3277 3292 3261 220 0.5 2 Lundy-Lk Cyn 38.0050 -119.2405 RGV5 A H 3002 3048 2957 295 0 1 Lundy-Lk Cyn 38.0106 -119.2408 RGV-Av A,R P-H 2979 3048 2911 295 0 1 Lundy-Lk Cyn 38.0086 -119.2407 RGV-Av A,R P, H 2972 3048 2896 295 0 1 Lundy-Lk Cyn 38.0042 -119.2407 RGV-Av A,R P, H 3002 3078 2926 295 0 1 Lundy-Lk Cyn 38.0068 -119.2407 RGV-Cl A H 2987 3048 2926 295 0 1 Lundy-Lk Cyn 37.9965 -119.2455 RGV-Cl A H 3018 3109 2926 330 1 3 Lundy-Lk Cyn 38.0113 -119.2412 RGV-Sc A H 2987 3048 2926 295 0 1 Lundy-Lk Cyn 37.9977 -119.2530 RGV-Sc A H 3002 3018 2987 100 0 1 Lundy-Lk Cyn 37.9935 -119.2558 RGV-Sc A H 3033 3048 3018 100 0 1 Lundy-Lk Cyn 38.0020 -119.2559 RGV-Sc A H 3246 3261 3231 90 0 1 Lundy-Lk Cyn 38.0062 -119.2410 RGV-Sc A,R P-H 2987 3048 2926 295 0 1 Lundy-Lk Cyn TYPE RGV-SC 37.9990 -119.2451 RGV-Sc R P-R 3072 3097 3048 310 0 2

6 Lundy-Lk Cyn TYPE RGV-TA 38.0114 -119.2411 RGV-Ta A H 2987 3048 2926 295 0 1 MammothCr-DuckPass 37.5665 -118.9826 BSC-Sc A H 3304 3408 3200 356 1 2 MammothCr-DuckPass 37.5642 -118.9819 BSC-Sc R H 3456 3468 3444 105 0.5 1 MammothCr-DuckPass 37.5693 -118.9844 BST-St A H 3199 3203 3194 322 1 2 MammothCr-DuckPass 37.5644 -118.9803 PGA-Cr A H 3422 3430 3414 344 0.5 1 MammothCr-DuckPass 37.5627 -118.9700 RGC-Cq A H 3216 3292 3139 30 0.5 3 MammothCr-DuckPass 37.5742 -118.9963 RGC-Va A H 3193 3292 3094 7 1 3 MammothCr-DuckPass 37.5672 -118.9778 RGC-Va A H 3223 3322 3124 18 1 3 MammothCr-DuckPass 37.5708 -118.9909 RGC-Va A H 3239 3277 3200 16 0.5 2 MammothCr-DuckPass 37.5671 -118.9813 RGC-Va A H 3310 3344 3277 2 1 3 MammothCr-DuckPass 37.5694 -118.9816 RGC-Va R P 3246 3292 3200 338 1 3 MammothCr-DuckPass 37.5667 -118.9598 RGV-Av A H 3261 3267 3255 308 0 2 MammothCr-DuckPass 37.5645 -118.9636 RGV-Cl A H 3223 3246 3200 275 0.5 2 MammothCr-DuckPass 37.5796 -118.9689 RGV-Sc A H 3206 3231 3182 198 0.5 2 MammothCr-DuckPass 37.5737 -118.9615 RGV-Sc A H 3264 3271 3258 210 0.5 2 MammothCr-DuckPass 37.5742 -118.9963 RGV-Ta A H 3208 3231 3185 275 0.5 2 MammothCr-DuckPass 37.5687 -118.9611 RGV-Ta A H 3208 3231 3185 303 0 2 Palisades-MidFkGlacier 37.0776 -118.4667 RGC-Mo A H 3642 3719 3566 14 0 3 Palisades-MidFkGlacier; TYPE RGC-Mo 37.0725 -118.4597 RGC-Mo A H 3658 3810 3505 12 0 3 Palisades-NFk 37.1257 -118.5120 RGC-Cq A H 3078 3231 2926 355 0.5 2 Palisades-NFk 37.1104 -118.4988 RGC-Cq A H 3434 3514 3353 350-0 0 1 Palisades-NFk 37.1102 -118.5127 RGC-Mo A H 3658 3719 3597 0 0 3 Palisades-NFk 37.1100 -118.5051 RGC-Mo A H 3703 3780 3627 0 0 3 Palisades-NFk 37.1126 -118.4850 RGC-Va A H 3376 3459 3292 330 1 3 Palisades-NFk 37.1144 -118.4934 RGV-Sc A H 3383 3475 3292 350-0 0 2 Palisades-NFk 37.1118 -118.4969 RGV-Sc A H 3414 3475 3353 350-0 0 2 Palisades-NFk 37.1152 -118.5063 RGV-Sc A H 3490 3566 3414 0 1 2 Palisades-NFk 37.1380 -118.5034 RGV-Sc R P 3475 3505 3444 180 0 2 Palisades-NFk 37.1404 -118.5082 RGV-Sc R P 3475 3505 3444 180 0 2 Palisades-NFk 37.1414 -118.5164 RGV-Sc R P 3475 3505 3444 180 0 2 Palisades-SFkGlacier 37.0783 -118.4502 RGC-Va A H 3520 3688 3353 5 1 4 Palisades-SFkGlacier TYPE BSC-SN 37.0889 -118.4526 BSC-Sn A H 3246 3261 3231 30 1 1 ParkerCyn 37.8326 -119.1985 BSC-Sn A H 3377 3386 3368 45 1 2 ParkerCyn 37.8284 -119.2019 BST-St A H 3484 3499 3469 10 1 2 ParkerCyn 37.8224 -119.2050 BST-St A H 3562 3597 3527 10 1 2 ParkerCyn 37.8205 -119.1908 MWA-So A H 3444 3475 3414 30 0 1 ParkerCyn 37.8241 -119.2108 MWA-So A H 3734 3780 3688 140 0.5 3

7 ParkerCyn 37.8139 -119.1886 MWA-So A H 3834 3926 3743 270 0.5 2 ParkerCyn 37.8142 -119.1981 MWA-So A H 3825 3871 3780 90 0.5 2 ParkerCyn 37.8178 -119.1959 RGC-Mo A H 3604 3627 3581 350-0 0 1 ParkerCyn 37.8243 -119.2089 RGC-Mo R P-R 3703 3749 3658 120 0.5 3 ParkerCyn 37.8175 -119.1605 RGC-Va A H 3063 3109 3018 -80 0.5 3 ParkerCyn 37.8190 -119.2086 RGC-Va A H 3665 3734 3597 0 0.5 3 ParkerCyn 37.8188 -119.1525 RGC-Va R P 2896 3048 2743 60 1 4 ParkerCyn 37.8233 -119.2010 RGV-Cl A H 3574 3612 3536 0 0.5 1 ParkerCyn 37.8199 -119.2062 RGV-Ta A H 3661 3694 3627 0 0.5 3 ParkerCyn 37.8168 -119.1564 RGV-Ta R P 3078 3109 3048 356 0.5 1 ParkerCyn 37.8167 -119.1551 RGV-Ta R P 3078 3109 3048 356 0.5 1 Parker Cyn, Koip Pass TYPE PGA-Cr 37.8142 -119.1950 PGA-Cr A H 3745 3745 3745 0 0.5 1 PineCr 37.3171 -118.7399 MWA-So A H 3414 3475 3353 45 0.5 2 PiuteCr-Wside, Glacier Divide 37.2383 -118.7832 RGC-Cq A H 3566 3597 3536 325 0.5 3 PiuteCr-Wside, Glacier Divide 37.2248 -118.7346 RGC-Mo A H 3566 3688 3444 10 0.5 3 PiuteCr-Wside, Glacier Divide 37.2255 -118.7398 RGC-Mo A H 3597 3658 3536 1 0 3 PiuteCr-Wside, Glacier Divide 37.2344 -118.7654 RGC-Mo A H 3612 3658 3566 38 0.5 3 PiuteCr-Wside, Glacier Divide 37.2422 -118.7759 RGC-Va A H 3459 3536 3383 355 1 4 PiuteCr-Wside, Glacier Divide 37.2253 -118.7297 RGC-Va A H 3536 3658 3414 3 1 3 PiuteCr-Wside, Glacier Divide 37.2315 -118.7584 RGC-Va A H 3551 3658 3444 5 1 3 PiuteCr-Wside, Glacier Divide 37.2324 -118.7617 RGC-Va A H 3520 3566 3475 17 1 3 PiuteCr-Wside, Glacier Divide 37.2272 -118.7481 RGC-Va A H 3566 3658 3475 5 1 3 PiuteCr-Wside, Glacier Divide 37.2391 -118.7702 RGC-Va A H 3536 3566 3505 8 0.5 3 PiuteCr-Wside, Glacier Divide 37.2286 -118.7448 RGC-Va A H 3749 3901 3597 358 1 4 PiuteCr-Wside, GoetheGlacier 37.2142 -118.7048 RGC-Mo A H 3627 3658 3597 8 0 3 PiuteCr-Wside, GoetheGlacier 37.2171 -118.7168 RGC-Mo A H 3703 3749 3658 2 0 3 PiuteCr-Wside, GoetheGlacier 37.2120 -118.7055 RGC-Va A H 3658 3719 3597 8 1 4 PiuteCr-Wside, GoetheGlacier 37.2142 -118.7048 RGC-Va A H 3658 3719 3597 12 1 4 PiuteCr-Wside, GoetheGlacier 37.2171 -118.7168 RGC-Va A H 3703 3749 3658 2 0.5 4 PiuteCr-Wside, GoetheGlacier 37.2174 -118.6829 RGC-Va A H 3719 3780 3658 340 1 3 PiuteCr-Wside, GoetheGlacier 37.2254 -118.6967 RGV-Av A H 3642 3658 3627 0 0 1 RobinsonCr-CattleCr 38.0891 -119.3527 RGC-Cq A H 3292 3322 3261 0 0.5 2 RobinsonCr-HorseCr 38.0971 -119.3736 RGC-Cq A H 3322 3383 3261 10 0.5 4 RobinsonCr-HorseCr 38.0880 -119.3582 RGC-Cq A H 3414 3566 3261 350-0 0.5 1 RobinsonCr-HorseCr 38.0971 -119.3807 RGC-Cq A H 3338 3383 3292 25 0.5 2 RobinsonCr-TamarackCyn 38.1214 -119.3200 BSC-Sc A H 2995 3042 2947 26 1 3 RobinsonCr-TamarackCyn 38.1292 -119.3135 BSC-Sn A H 2957 2960 2954 280 0 1

8 RobinsonCr-TamarackCyn 38.1270 -119.3138 BSC-Sn A H 2967 2969 2966 280 0 1 RobinsonCr-TamarackCyn 38.1200 -119.3175 BST-St A H 3001 3045 2957 5 1 2 RobinsonCr-TamarackCyn 38.1142 -119.3178 BST-St A H 3075 3077 3074 1 0.5 2 RobinsonCr-TamarackCyn 38.1239 -119.3061 MWA-So A H 3277 3322 3231 360 0.5 3 RobinsonCr-TamarackCyn 38.1248 -119.3084 PGA-Cr A? H 3267 3267 3266 360 0.5 1 RobinsonCr-TamarackCyn 38.1077 -119.3227 RGC-Cq A H 3178 3191 3164 350 1 2 RobinsonCr-TamarackCyn 38.1040 -119.3194 RGC-Cq A H 3261 3292 3231 3 1 2 RobinsonCr-TamarackCyn 38.1114 -119.3200 RGC-Va A H 3097 3109 3085 32 1 3 RobinsonCr-TamarackCyn 38.1342 -119.3162 RGC-Va R H 2871 2957 2786 360 1 4 RobinsonCr-TamarackCyn 38.1148 -119.3190 RGV-Cl A H 3066 3072 3060 22 0.5 2 RobinsonCr-TamarackCyn 38.1152 -119.3200 RGV-Sc A H 3054 3060 3048 30 0.5 2 RobinsonCr-TamarackCyn 38.1292 -119.3135 RGV-Sc R P 2963 2966 2960 280 0 2 RobinsonCr-TamarackCyn 38.1270 -119.3138 RGV-Sc R P 2975 2981 2969 280 0 1 RobinsonCr-TamarackCyn 38.1255 -119.3139 RGV-Sc R P 2976 2981 2970 275 0.5 2 RobinsonCr-TamarackCyn 38.1236 -119.3147 RGV-Sc R P 2982 2993 2972 330 0.5 2 RobinsonCr-TamarackCyn, TYPE RGC-PO 38.1294 -119.3248 RGC-Po R H 3024 3034 3014 50 0.5 2 RobinsonCrUpper-CrownPT/Little Slide Cyn 38.1180 -119.4186 RGC-Va A H 3124 3200 3048 350 0.5 2 RobinsonCrUpper-CrownPT/Little Slide Cyn 38.1155 -119.4552 RGC-Va A H 3098 3139 3057 360 0.5 2 RobinsonCrUpper-CrownPT/Little Slide Cyn 38.1176 -119.4544 RGC-Va R P 2996 3170 2822 7 1 3 RockCr-MainCyn 37.4476 -118.7286 RGV-Cl A H 3162 3170 3155 335 0.5 2 RockCr-MainCyn 37.4116 -118.7790 RGV-Cl A H 3627 3719 3536 40 0.5 2 RockCr-MainCyn 37.4476 -118.7286 RGV-Cl R P-R 3162 3170 3155 335 0.5 2 RockCr-MainCyn 37.4421 -118.7323 RGV-Sc A H 3185 3200 3170 330 0 2 RockCr-MainCyn 37.4421 -118.7323 RGV-Sc R P 3139 3170 3109 330 0 2 RushCr-SpookyAlgerBlacktop 37.8076 -119.1899 MWA-So A H 3597 3719 3475 160 0.5 3 RushCr-SpookyAlgerBlacktop 37.7967 -119.1946 RGC-Cq A H 3505 3566 3444 38 0 1 RushCr-SpookyAlgerBlacktop 37.7405 -119.1282 RGC-Va A H 3039 3121 2957 0 0.5 2 RushCr-SpookyAlgerBlacktop 37.7453 -119.1273 RGV-Sc A H 3018 3048 2987 270 0 2 Taboose Pass-Eside,StripedMTN 36.9685 -118.4025 ? R T 3856 3932 3780 30 1 3 Taboose Pass-Wside,SFkKings 36.9710 -118.4079 RGC-Cq A H 3551 3627 3475 340 0 1 Taboose Pass-Wside,SFkKings 36.9693 -118.4099 RGC-Cq A H 3612 3627 3597 340 0 1 Taboose Pass-Wside,SFkKings 36.9594 -118.4130 RGC-Va A H 3597 3658 3536 5 TO 10 1 3 Taboose Pass-Wside,SFkKings 36.9634 -118.4190 RGV-Sc A H 3520 3536 3505 345 0 1 Taboose-MtPerkins,ArmstrongCyn 36.9268 -118.3725 RGC-Va A H 3231 3414 3048 40 1 4 Tioga Crest, Gaylor 37.9307 -119.2727 BSC-Sn A H 3197 3347 3048 20-158 0.5 1 Upper LV Cyn-Tioga Crest-Conness 37.9762 -119.2981 BSC-Sc A H 3117 3140 3094 20 1 2 Upper LV Cyn-Tioga Crest-Conness 37.9764 -119.2931 BSC-Sc A H 3134 3174 3094 358 0.5 3

9 Upper LV Cyn-Tioga Crest-Conness 37.9876 -119.3087 BSC-Sc A H 3155 3200 3109 35 1 3 Upper LV Cyn-Tioga Crest-Conness 37.9704 -119.2764 BSC-Sc A H 3130 3139 3121 75 0.5 2 Upper LV Cyn-Tioga Crest-Conness 37.9711 -119.2778 BSC-Sc A H 3130 3139 3121 40 0.5 2 Upper LV Cyn-Tioga Crest-Conness 37.9769 -119.3110 BSC-Sc A H 3318 3325 3310 163 0.5 2 Upper LV Cyn-Tioga Crest-Conness 37.9759 -119.3140 BSC-Sc A H 3391 3414 3368 153 0 2 Upper LV Cyn-Tioga Crest-Conness 37.9738 -119.2840 BSC-Sc R P 3185 3277 3094 20 0.5 3 Upper LV Cyn-Tioga Crest-Conness 37.9767 -119.3081 BST-St A H 3228 3216 3240 70 1 2 Upper LV Cyn-Tioga Crest-Conness 37.9743 -119.3144 BST-St A H 3353 3414 3292 93 1 2 Upper LV Cyn-Tioga Crest-Conness 37.9689 -119.2741 PGA-NS ? ? 3069 3071 3066 57 0 2 Upper LV Cyn-Tioga Crest-Conness 37.9731 -119.2786 PGA-NS ? ? 3078 3086 3071 50 0 2 Upper LV Cyn-Tioga Crest-Conness 37.9755 -119.2925 RGC-Cq A H 3133 3210 3056 348 1 3 Upper LV Cyn-Tioga Crest-Conness 37.9706 -119.3122 RGC-Mo A H 3418 3475 3360 5 0 3 Upper LV Cyn-Tioga Crest-Conness 37.9720 -119.3167 RGC-Mo A H 3486 3536 3437 345 1 4 Upper LV Cyn-Tioga Crest-Conness 37.9727 -119.2924 RGC-Va A H 3293 3310 3277 340 1 3 VirginiaCr 38.0514 -119.2846 BSC-Sc A H 3299 3399 3200 162 1 2 VirginiaCr 38.0405 -119.2796 BSC-Sc A H 3414 3505 3322 7 1 2 VirginiaCr 38.0396 -119.2812 BSC-Sc A H 3490 3536 3444 353 1 2 VirginiaCr 38.0581 -119.2796 BSC-Sc A,R H 3322 3414 3231 175 0.5 3 VirginiaCr 38.0541 -119.2725 BSC-Sc A,R H 3231 3414 3048 160 0.5 3 VirginiaCr 38.0518 -119.2807 BSC-Sn A H 3197 3200 3193 158 0.5 1 VirginiaCr TYPE MWA-SO 38.0433 -119.2748 MWA-So A H 3331 3432 3231 89 0.5 2 VirginiaCr 38.0394 -119.2902 RGC-Cq A H 3322 3353 3292 35 0.5 1 VirginiaCr 38.0387 -119.2881 RGC-Cq A H 3399 3414 3383 3 0.5 2 VirginiaCr 38.0368 -119.2871 RGC-Cq A H 3459 3475 3444 355 0.5 1 VirginiaCr 38.0518 -119.2830 RGV-Cl A,R H 3216 3231 3200 160 0 2 Warren Front 37.9926 -119.2015 BSC-Sn A H 3304 3316 3292 70 0.5 1 Warren Front 37.9754 -119.1919 MWA-So A H 3231 3261 3200 48 0.5 2 Warren Front 37.9805 -119.1900 PGA-Cr R P 3132 3132 3132 82 0.5 1 Warren Front 37.9794 -119.2023 RGC-Cq A H 3280 3292 3267 15 0.5 1 Warren Front 37.9798 -119.2097 RGC-Mo R P-R 3368 3383 3353 45 0.5 1 Warren Front 37.9745 -119.1935 RGC-Mo R P 3231 3261 3200 48 0.5 2 Warren Front 37.9815 -119.1892 RGC-Va A H 3110 3139 3081 82 1 3 Warren Front 37.9864 -119.1965 RGC-Va R P 3246 3444 3048 40-80 1 4 YNP Cathedral 37.8384 -119.4248 RGC-Cq A H 3039 3050 3029 26 0.5 1 YNP-DanaFkTuolomne 37.8844 -119.2235 BSC-Sc A H 3536 3658 3414 300 0.5 2 YNP-DanaFkTuolomne 37.8856 -119.2148 BSC-Sc A H 3536 3658 3414 300 0.5 2 YNP-DanaFkTuolomne 37.8885 -119.2134 BSC-Sc A H 3536 3658 3414 300 0.5 2

10 YNP-DanaFkTuolomne 37.8878 -119.2330 BSC-Sn A H 3216 3231 3200 305 1 1 YNP-DanaFkTuolomne 37.9053 -119.2462 BSC-Sn A H 3399 3444 3353 260 1 1 YNP-DanaFkTuolomne 37.9090 -119.2389 BSC-Sn A H 3505 3536 3475 260 0.5 1 YNP-DanaFkTuolomne 37.9081 -119.2420 BSC-Sn A H 3505 3536 3475 260 0.5 1 YNP-DanaFkTuolomne 37.8890 -119.2335 BST-St A H 3254 3307 3200 270 1 2 YNP-DanaFkTuolomne 37.8830 -119.2118 MWA-So A H 3673 3749 3597 320-350 0.5 2 YNP-Matterhorn 38.0723 -119.3891 RGC-Cq A H 3429 3505 3353 350-0 0.5 3 YNP-ParkerPassKunaPkCrest 37.8261 -119.2327 BSC-Sc A H 3399 3475 3322 27 1 4 YNP-ParkerPassKunaPkCrest 37.8284 -119.2264 BSC-Sc A H 3347 3353 3341 348 0.5 2 YNP-ParkerPassKunaPkCrest 37.8380 -119.2307 BSC-Sn A H 3261 3292 3231 4 0.5 1 YNP-ParkerPassKunaPkCrest 37.8338 -119.2087 BST-St A H 3335 3338 3331 355 1 2 YNP-ParkerPassKunaPkCrest 37.8326 -119.2374 BST-St A H 3490 3505 3475 62 1 2 YNP-ParkerPassKunaPkCrest 37.8281 -119.2217 MWA-So A H 3566 3780 3353 325 0.5 4 YNP-ParkerPassKunaPkCrest 37.8335 -119.2265 PGA-La A H 3338 3339 3336 2 0.5 1 YNP-ParkerPassKunaPkCrest 37.8327 -119.2383 PGA-La A H 3507 3510 3505 3 0.5 1 YNP-ParkerPassKunaPkCrest 37.8286 -119.2275 GA-La,PGA-N A H 3341 3339 3342 348 1 2 YNP-ParkerPassKunaPkCrest 37.8480 -119.2591 RGC-Cq A H 3402 3420 3383 45 0.5 2 YNP-ParkerPassKunaPkCrest 37.8480 -119.2572 RGC-Cq A H 3450 3487 3414 23 0.5 2 YNP-ParkerPassKunaPkCrest 37.8336 -119.2469 RGC-Cq A H 3491 3536 3447 2 0.5 2 YNP-ParkerPassKunaPkCrest 37.8356 -119.2444 RGC-Cq A H 3498 3536 3459 7 0 1 YNP-ParkerPassKunaPkCrest 37.8287 -119.2113 RGC-Cq A H 3539 3572 3505 0-10 0.5 2 YNP-ParkerPassKunaPkCrest 37.8222 -119.2235 RGC-Cq A H 3581 3627 3536 355-5 0 2 YNP-ParkerPassKunaPkCrest 37.8438 -119.2518 RGC-Mo R H 3438 3450 3426 10 1 2 YNP-ParkerPassKunaPkCrest 37.8500 -119.2574 RGC-Mo R H 3360 3429 3292 83 1 2 YNP-ParkerPassKunaPkCrest 37.8487 -119.2596 RGC-Va A H 3417 3466 3368 55 1 3 YNP-ParkerPassKunaPkCrest TYPE BSC-SC 37.8262 -119.2246 BSC-Sc A H 3536 3749 3322 325 0.5 4 YNP-SlideCyn 38.0880 -119.4086 RGC-Cq A H 3322 3353 3292 10 0.5 2 YNP-SlideCyn 38.0893 -119.4033 RGC-Va A H 3261 3353 3170 7 0.5 2 YNP-SlideCyn 38.0911 -119.4091 RGC-Va R P 3213 3255 3170 10 0.5 2 YNP-Tenaya 37.8302 -119.4415 RGC-Va A H 2961 3002 2921 340 1 3 YNP-TuolomneJohnsonPk 37.8273 -119.3551 BSC-Cl A H 3261 3322 3200 0 0.5 2 YNP-TuolomneJohnsonPk 37.8326 -119.3496 MWA-So A H 3322 3353 3292 270 0.5 1 YNP-TuolomneJohnsonPk 37.8273 -119.3551 RGC-Va R H 3261 3322 3200 1 0.5 2 YNP-TuolomneJohnsonPk 37.8296 -119.3536 RGV-Sc A H 3299 3307 3292 270 0 1

1 See Text-Table 1 for explanation of classification codes

11 2 A = active; R = relict 3 H = Holocene; R = Pleistocene, Recess Peak; P = Pleistocene, pre-Recess Peak (Late Glacial Maximum); one feature is scored T, Tertiary 4 1 = Longer than wide; 0.5 = Equal width and length; 0 = Wider than long 5 1 = 0.5 ha; 2 = 5 ha; 3= 50 ha; 4 ≥ 400 ha

12