The Great Basin Naturalist Published at Provo, Utah, by B righam Young U niversity ISSN 0017-3614 Volume 52 Ju n e 1992 N o . 2 Great Basin Naturalist52(2), pp, 95-121 RED BUTTE CANYON RESEARCH NATURAL AREA: HISTORY, FLORA, GEOLOGY, CLIMATE, AND ECOLOGY James R. Ehleringer , Lais A. AnKw, Ted Aroow, Irving B. McNulty , and Norman C. Negus Abstract — Red Butte Canyon is a protected near pristine canyon entering Salt Lake Valiev. Utah It contains a well-developed riparian zone and a perennial stream; hillside vegetation ranges from grasslands on the lower limits to Douglas-fir and aspen stands at the upper elevations In this paper we describe the history of human impact, natural history aspects of climate, geology, and ecology and fauna! and floral information for key species in the canyon. The role and importance of Research Natu ral Areas is discussed, particularly with respect to the need to protect Red Butte Canyon—one of the few remaining undisturbed riparian ecosystems in the Intermountain West. Key wordsi grassland, IntvrmoHntain West, oak-maple, plant adaptationr Red Butte Canyon, Research Natural Area, riparian ecology. Red Butte Canyon, one of many canyons in stantia] value to society. These might include the Wasatch Range of Utah, opens westward unique geological features, endangered plant into Salt Lake Valley, immediately east of the and animal species, or areas of particular value University of Utah (Fig. 1). Like most canyons for scientific research as baseline bench marks along the Wasatch Front, it is a grassland at the of ecosystems that have been largely destroyed lowest elevations, is forested at its upper end, by human impact. In the case of Red Butte and has a perennial stream. What makes this Canyon, the RNA designation was given canyon u nusual is its history. The canyon was the because this canyon is one of the few remaining watershed for Fort Douglas, the U.S. Army post (if not the last) undisturbed watersheds in the built in 1862 that overlooked Salt Lake City. As Great Basin. The U.S. Forest Service report a protected watershed, these lands were, for the proposing that Red Butte Canyon be declared a most part, kept free from grazing, farming, and Research Natural Area described ihe canyon as other human-impact activities. When the U.S. a living museum and biological librarv of a Army declared these lands surplus in 1969, the size that exists nowhere else in the Great Basin U.S. Forest Service assumed responsibility for . an invaluable bench mark in ecological the canvon. Since that time. Red Butte Can von J J time." The Red Butte Canyon RNA is unique has been kept in its protected state and desig­ because it is a relatively undisturbed watershed nated a Research Natural Area (RNA). adjacent to a major metropolitan area (Salt Lake The Research Natural Area designation Valley). To protect this valuable resource, access denotes an area that has been set aside because to the Red Butte Canyon RNA has been largely it contains unusual or unique features of sub­ restricted to scientific investigators. One of the 96 G r ea t Ba sin N a t u r a l ist [V olum e 52 Salt Lake City'////////// Intl. Airport ////////// ' / / > / / / / / / / * / w /s/s/sr/// Pinecrest f/f/ff/SJf/'fS, rs / / / / i<y / / / / « 555 University s s s s s s s $ s s s s s s S a lt s s s w s s , /////A $ S s s / s s . L a k e "SSSSfSSSSfSSSSSSf f s j f j s , ‘ J f j f / j f s / s s s . % s / j s s s * C ity yv /v /y/ /// f s s j s s s / / / / / / z > rr f f s t / f f f h /////////j' ////V JsSSS/SJ/SSfSSSA/SSffSSSfffSSS/SSfJ-SjrssSfSsS fftf. < 8 0 c mile ///////■ kilometers « / y / y / Mitt C^eek Cnyn Fig. 1, Location of Red Butte Canyon and oHier sites referred to in text, goals of the RNA Program is to protect and of biotic communities along an elevation gradi­ preserve a representative array of all significant ent from about 1530 m (5020 ft) on the west end natural ecosystems and their inherent processes to more than 2510 in (8235 ft) at the crest. as baseline areas. A second goal is to conduct The purpose o f this paper is to provide a brief research on ecological processes in these areas description of the his tor)-; flora, geology, cli­ to learn more about the functioning of natural mate, and ecology of diis unusual and valuable versus manipulated or disturbed ecosystems. resource. There is increasing interest in Red Research activities in the Red Butte Canyon Butte Canyon, in part by scientific investigators RNA are directed at both of these goals: under* because of its utility as a protected, undisturbed standing basic ecological processes (physiologi­ watershed, anti in part by curious citizens from cal adaptation, drought adaptation, nutrient the nearby Salt Lake Valley. Yet. there Inis not cycling, etc.) and also the impact of humans on been an overall reference available for those our canyons through both airborne (air pollu­ interested in general features of the canyon or tion, acid rain, etc.) and land-related (grazing, past ecological studies within the canyon. Most human traffic, etc.) activities. The latter are of the information on Red Butte Canyon is conducted through comparison of Red Butte scattered. With the closure of Fort Douglas in with other canyons along the Wasatch Range. 1991, many of the historical records will becom e In size, Red Butte Canyon is relatively small more difficult to access. It is hoped that the compared with other drainages along the, synthesis presented in this paper will provide Wasatch Front. The drainage basin covers an area of approximately 20.8 km2 (5140 acres) the necessary background for those interested (Fig. 2). The drainage arises on the east from a in the history and ecology of the Red Butte minor divide between City Creek and Emigra­ Canyon RNA. Irving McNulty first summarizes tion canyons and drains to the west. The canyon the history of the canyon, followed by Ted lias two main forks (Knowltons and Parleys) and Amows description of geology and soils, James many side canyons. Near the canyon base, a Ehleringer contributed the hydrology, climate, reservoir was constructed earlier this century to and plant ecology sections. The section on vas­ provide a more stable water supply to Fort cular flora was prepared by Lois A mow, and Douglas. The diversity of slope and aspect com ­ Norman Negus wrote the mammalian and avian binations of the terrain contributes to a variety fauna sections. 1992] R e d B u t t e C a n y o n R e s e a r c h N a tu ra l A r ea 99 Table I. Description of geological formations in Red protect the water supply of Fort Douglas. This Butte Canyon, law preven ted any sale of land in the canyon or 1 ............. ■ ■ i ■■ ■ I. - ■ ■■ k m . II ■ a. ftllMlI II, II, I i ■■ ................. fcl *j, . Cenozoic- era, Quaternary' system, Holocene series further watershed development. In 1906 the fa Fhod-phin alhmwm. Sand, cobbly to silty, dark gray at U.S. Army built a dam on Red Butte Creek to top; grading downward to medium to light gray, sandy to supply additional water for Fort Douglas. The cobbly gravel; locally bouideiy. fe Engime/'ed fill Selected earth material that has been present dam was constructed between 1928 and emplaced and compacted, 1930, and the reservoir provided water for Fort Cenozoic era, Quaternary and Tertiary systems, Douglas until its closure in 199L Holocene and Pleistocene series There are no grazing records available for fg Alluvial-fan deposits. Bouldery to clayey silt, dark gray to Red Butte Canyon prior to 1909, by which time brown; rocks angular to subrounded. Id landslide deposits. Composition similar to material the U nited States had acquired title to most of up slope. the land in the canyon, Cottam and Evans Mesozoic era, Jurassic system (1945) reported evidence of some gully erosion Jtc Ttuin Creek Limestone. Brownish gray and pale gray to occurring in the canyon prior to 1909 and pale yellowish gray silty limestone, intercalated with assumed it was due to overgrazing. Although we greenish gray shale. lack quantitative data, there are a few isolated Mesozoic era, Jurassic? and Driassic? systems incidents indicating the occurrence of grazing, JTn Nugget Sandstone. Pale pinkish buff, fine- to medium- grained, well-sorted sandstone that weathers orange- i ncluding an 1S54 report of a young man drown­ brown. Massive outcrops form the ridge called Hed Butte. ing in a flash flood in Red Butte Canyon while Mesozoic era, Triassic system herding animals. Over fort)' head of oxen used Tau Ankareh Formation, upper member. Reddish brown, to haul sandstone from the quarry in the iate reddish purple, grayish red, or bright red shale, siltstone, 1800s remained in the canyon during that time. and sandstone. Tag Ankareh Formation, Gattra Grit Member. White to pale In 1869 the War Department appointed a puiple, thick-bedded, crossbedded, pebbly quartzite. herder to control loose cattle grazing on Fort Forms a prominent white ledge for lon$ distances. Douglas and in the canyon. In 1890 three squat­ Tam Ankat'eh Formation, Mahogany Member, Reddish brown, reddish purple, grayish red, or bright red shale, ters had settled into the canyon., and their forty siltstone, and sandstone. head of cattle were grazing in the Parleys Fork Tt Thaunes Formation. Medium to light gray, fossiliferous, area before being evicted. By 1909 the Army locafly nodular limestone., limy siltstone, and sandstone, had built a gate at the mouth of the canyon to Tiv Woodside Shale.