Level 4 Potential Conservation Area (PCA) Report Name Ken Caryl Hogback Complex Site Code S.USCOHP1*1920
IDENTIFIERS Site ID 1296 Site Class PCA Site Alias Dutch Creek Ridge Site Alias Deer Creek North Site Alias Deer Creek Hogback Network of Conservation Areas (NCA) NCA Site ID NCA Site Code NCA Site Name - No Data County
SITE DESCRIPTION Site Description The Ken Caryl hogback complex is a linear corridor formed by two parallel hogbacks that run north-south and are separated by a narrow valley. The hogback ridges provide habitat for rare plants and healthy grassland and shrub communities on the outcrops of Dakota sandstone and Niobrara shale. Two major roads, Ken Caryl Avenue and Deer Creek Canyon Road cut through the hogbacks in the north and south portions of the site. A major state highway, C-470 crosses through the northern section and is just east of the hogback complex in the southern part of the site. Several perennial streams dissect the hogbacks, although Dutch Creek is the only perennial stream not adjacent to a road. On the hogbacks xeric tallgrass prairie ( Andropogon gerardii - Schizachyrium scoparium) is found along the lower slopes with shrub communities dominated by mountain mahogany (Cercocarpus montanus), skunkbrush (Rhus aromatica subsp. trilobata) and Gambel's oak (Quercus gambelii) with scattered ponderosa pines (Pinus ponderosa) and Rocky Mountain juniper (Juniperus scopulorum). Black-tail prairie dog (Cynomys ludovicianus) communities, rare butterflies including the Ottoe skipper (Hesperia ottoe) and Arogos skipper (Atrytone arogos), northern leopard frog (Lithobates pipiens) and a nesting Prairie Falcon (Falco mexicanus) are also found in the valley and on the hogbacks. In addition, a Long-eared Owl (Asio otus) was documented nesting in the Gambel's oak woodland associated with the hogbacks. Key Environmental Factors Physical topography including hogbacks, streams, sandstone and shale outcrops are all factors that contribute to the existing habitats that support the diversity of plants, animals and plant communities that currently exist. In addition, the surrounding large land areas that have been not been developed are also a significant factor. Climate Description The Ken Caryl hogbacks are located at the edge of the foothills on the east side of the Rocky Mountains in central Jefferson County. The climate supports more xeric vegetation due to the location in the rain shadow of the nearby mountains. The nearby weather station at Kassler, CO between 1918 and 2010 recorded an average annual precipitation of 17.6 inches. Snowfall is greatest in February through April and summer rains peak in April and May. The average annual maximum temperature is 65.9°F (18.8 °C) and the average annual minimum is 36.4°F (2.4°C, WRCC 2006). Land Use History Native Americans, homesteaders and ranchers have made use of this landscape for hundreds of years. Agriculture and ranching have impacted large areas especially the grassy valleys. Fire suppression has also been a factor in the history of this site. In 1989, the hogback areas were initially recognized as significant natural features and were given priority as high quality areas for education, recreation and conservation (Pague et al. 1993). A large portion of the land is County Open Space, private open space and lands owned by the Foothills Recreation District. The Open Space managers have provided weed and prairie dog management for over a decade that has supported the natural environment in these areas Cultural Features Several archaeological sites have been located in the area by the Colorado Archaeological Society. More than 1,000 Woodland Indian artifacts have been found. The Bradford House III archaeological site was put on the National Register of Historic Places in 1980. New sites are being explored.
Minimum Elevation 5,800.00 Feet 1,767.84 Meters
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Maximum Elevation 6,540.00 Feet 1,993.39 Meters SITE DESIGN Site Map Y - Yes Mapped Date 02/24/2012 Designer Smith, P.F. and J.R. Sovell Boundary Justification The boundary includes the parallel hogbacks and their slopes. It includes all known xeric tallgrass prairie remnants located in the valley and on the lower slopes of the hogbacks and the known populations of rare plants and animals. A disjunct group of hills to the east of the hogbacks, just east of I-470, is included because of a dense population of the rare Bell's twinpod hybrid. This is a very large site and was originally drawn during the first Natural Heritage Inventory of Jefferson County twenty years ago (Pague et al.1993). The new boundaries match closely to those drawn previously except that populations of what was then identified as Bell's twinpod (Physaria bellii) were not all included. The new boundary incorporates these areas because new and existing populations of the twinpod (now recognized as a hybrid) were observed in areas in between these hogbacks. The ecological processes such as hydrology, natural migration, dispersal and pollination are all supported by the surrounding habitat which is important to the long-term persistence of the occurrences. The boundary was digitized while referencing digital color orthophoto quad and a 1:24,000 digital quad. Primary Area 4,628.86 Acres 1,873.24 Hectares SITE SIGNIFICANCE Biodiversity Significance Rank B2: Very High Biodiversity Significance Biodiversity Significance Comments Most significant, are the excellent (A-ranked) and good (B-ranked) occurrences of Bell's twinpod hybrid (Physaria x1), a globally critically imperiled (G1Q/S1) plant. Currently, the only known populations in the world of this species are within this site. The hogback complex supports two fair (C-ranked) occurrences of a globally imperiled (G2?/S2) big bluestem-little bluestem (Andropogon gerardii-Schizachyrium scoparium) xeric tallgrass plant community, found in the northern and southern sections on the hogback slopes. Some of the patches include dense stands of big and little bluestem ( Schizachyrium scoparium) while some areas have more scattered populations forming a mosaic with other native grasses and forbs. The site also supports two occurrences of globally vulnerable and state rare butterflies, the Ottoe skipper (G3G4/S2) and Arogos Skipper (G3/S2). A rare grass, the forked threeawn (Aristida basiramea), is known from two locations along sandstone outcrops of these hogbacks. Forked threeawn is globally stable but very rare in the state (G5/S1), a fair (C-ranked) and a historical (H-ranked) occurrence have been documented on the hogbacks. A poor (D-ranked) occurrence of a globally stable but state critically imperiled species (G5/S1), red stemmed spring beauty (Claytonia rubra,) which is currently known from less than five known locations in the state (CNHP 2011), was also found on the hogbacks. Other Values Rank No Data Other Values Comments Within the site is also a historical (H-ranked) occurrence of the state vulnerable northern leopard frog (G5/S3). In addition, a Long-eared Owl (Asio otus) was documented nesting in the Gambel's oak woodland associated with the hogbacks. Long-eared Owls are not tracked but are an uncommon and notable species indicative of the quality of the habitat. Note on Physaria x1: The newly identified hybrid species Physaria x1 was genetically determined to be a cross between two rare plants that are both Colorado endemics, Rydberg twinpod (Physaria vitulifera) and Bell's twinpod (Physaria bellii - Kothera et al. 2007). In the Natural Heritage Inventory conducted in 1992-93 (Pague et al. 1993), these plants were identified as Bell's twinpod ( Physaria bellii), although, different surveyors noted the plants at this site appeared to be hybrid species and noted research should be conducted on these plants. Resulting from the genetic work of Kothera (2007) and the geographical study of a local scientist, Bill Jennings (2004), the Natural Heritage Program was able to assess the new ranges of the twinpod species in Colorado. Since the 1993 report, these observations have been genetically verified from samples collected at this site. Although the hybrid has been verified, it has not yet been formally named in the literature and is currently listed in the Natural Heritage Program database as Physaria x1. ASSOCIATED ELEMENTS OF BIODIVERSITY Element Global State Driving State ID State Scientific Name State Common Name Rank Rank Site Rank
Copyright © 2018. Colorado State University. Colorado Natural Heritage Program. All Rights Reserved. Print Date 3/3/2018 2 Level 4 Potential Conservation Area (PCA) Report Name Ken Caryl Hogback Complex Site Code S.USCOHP1*1920
24870 Andropogon gerardii - Schizachyrium scoparium Xeric Tallgrass Prairie G2? S2 N Western Great Plains Grassland 23792 Aristida basiramea Forktip three-awn G5 S1 N 24870 Andropogon gerardii - Schizachyrium scoparium Xeric Tallgrass Prairie G2? S2 N Western Great Plains Grassland 23792 Aristida basiramea Forktip three-awn G5 S1 N 16895 Atrytone arogos Arogos Skipper G3 S2 N 19893 Hesperia ottoe Ottoe Skipper G3G4 S2 N 18389 Lithobates pipiens Northern Leopard Frog G5 S3 N 22001 Claytonia rubra Redstem spring beauty G5 S1 N 44187 Physaria x 1 GNA S1 Y 44187 Physaria x 1 GNA S1 Y LAND MANAGMENT ISSUES Land Use Comments The majority of the lands are managed as open space with non-motorized trails throughout the area. Some of the areas are not easily accessible and are afforded more protection. A few grasslands are actively mowed for hay in the southern portion of the site on the eastern slopes. A large portion is owned by a private corporation. Residential developments are very dense in the surrounding landscape as is typical for the Rocky Mountain Front Range. Associated with the heavy residential developments are a number of very heavily used roads.
Natural Hazard Comments Steep terrain, loose rocky slopes, lightning and rattle snakes are the typical dangers that one would expect on this terrain.
Exotics Comments An excellent example of good weed and prairie dog management has been occurring on the managed lands in the hogbacks on the northern section of the site especially in the vicinity of the tallgrass prairie. A concerted effort of weed management including controlled burns has been used with success to promote native vegetation. In addition, methods have been designed to sustain the prairie dog population. The exotics on the south section are probably of greatest concern and include Scotch thistle ( Onopordum acanthium), musk thistle (Carduus nutans), diffuse knapweed (Acosta diffusa), toadflax (Linaria vulgaris), and Canada thistle (Breea arvensis) which are all B-Listed noxious weeds (Colorado Weed Management Association 2009). However, the planted pasture grasses especially smooth brome (Bromopsis inermis), orchard grass (Dactylus glomerata) and Kentucky bluegrass (Poa pratensis) have invaded and dominate many of the disturbed and agricultural areas and streambanks located along the drainages. The pasture grasses are difficult to control without damaging other aspects of ecosystems and are not included on noxious weed lists. Other common exotics include cheatgrass (Anisantha tectorum), and common mullein (Verbascum thapsus) which are often so widespread in modern landscapes (C-listed species) that they are difficult to treat effectively. Offsite No Data Information Needs No Data REFERENCES
Copyright © 2018. Colorado State University. Colorado Natural Heritage Program. All Rights Reserved. Print Date 3/3/2018 3 Level 4 Potential Conservation Area (PCA) Report Name Ken Caryl Hogback Complex Site Code S.USCOHP1*1920
Reference ID Full Citation 198880 Colorado Natural Heritage Program. 2013. Biodiversity Tracking and Conservation System (BIOTICS). Colorado Natural Heritage Program, Colorado State University, Fort Collins. 198884 Colorado Weed Management Association (CWMA). 2009. Noxious weeds of Colorado.10th Edition. 198811 Jennings, W.F. 2004. The Status of Physaria vitulifera in Wyoming. 198904 Kothera, L, S.M. Ward and S.E. Carney. 2007. Assessing the threat from hybridization to the rare endemic Physaria bellii Mulligan (Brassicaceae). Biol. Cons. 140:110-118. 170746 Pague, C., Rondeau, R. and Duff, M. 1993. Natural Heritage Inventory of Jefferson County, CO. Colorado Natural Heritage Program. Prepared for Jefferson County Open Space. 119 pp. 198887 Rocchio, J. 2007. Floristic quality assessment indices for Colorado plant communities. Prepared for the Colorado Department of Natural Resources Division of Wildlife, Wetlands Program, Denver, Colorado and the U.S. Environmental Protection Agency, Region 8,Denver, Colorado. Colorado Natural Heritage Program, Fort Collins, Colorado 198851 Sovell, J., P. Smith, D. Culver, S. Panjabi and J. Stevens. 2012. CNHP Final Report: Survey of Critical Biological Resources in Jefferson County, Colorado. Colorado Natural Heritage Program, Fort Collins, CO. 198883 WRCC. 2011. Western Regional Climate Center. Division of Atmospheric Sciences, Desert Research Institute. Reno, Nevada.
LOCATORS Nation United States Latitude 393402N State Colorado Longitude 1050824W Quad Code Quad Name 39105-E1 Littleton 39105-E2 Indian Hills Watershed Code Watershed Name 10190002 Upper South Platte VERSION Version Date 02/24/2012 Version Author Smith, P.F. and J.R. Sovell DISCLAIMER
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These data are a product and property of Colorado State University, Colorado Natural Heritage Program (CNHP). These data are strictly "on loan" and should be considered "works in progress". Data maintained in the Colorado Natural Heritage Program database are an integral part of ongoing research at CSU and reflect the observations of many scientists, institutions and our current state of knowledge. These data are acquired from various sources, with varying levels of accuracy, and are continually being updated and revised. Many areas have never been surveyed and the absence of data in any particular geographic area does not necessarily mean that species or ecological communities of concern are not present. These data should not be regarded as a substitute for on-site surveys required for environmental assessments. Absence of evidence is NOT evidence of absence. Absence of any data does not mean that other resources of special concern do not occur, but rather CNHP files do not currently contain information to document this presence. CNHP is not responsible for whether other, non-CNHP data providers have secured landowner permission for data collected. These data are provided for non-commercial purposes only. Under no circumstances are data to be distributed in any fashion to outside parties. To ensure accurate application of data, tabular and narrative components must be evaluated in conjunction with spatial components. Failure to do so constitutes a misuse of the data. The Colorado Natural Heritage Program shall have no liability or responsibility to the data users, or any other person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the data, including but not limited to any interruption of service, loss of business, anticipatory profits or indirect, special, or consequential damages resulting from the use of operation of the data. Data users hereby agree to hold CNHP, Colorado State University, and the State of Colorado harmless from any claim, demand, cause of action, loss, damage or expense from or related to data users use of or reliance on the data, regardless of the cause or nature thereof, and even in the event that such cause is attributable to the negligence or misconduct of CNHP. These data are provided on an as-is basis, as-available basis without warranties of any kind, expressed or implied, INCLUDING (BUT NOT LIMITED TO) WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. Although CNHP maintains high standards of data quality control, CNHP, Colorado State University, and the State of Colorado further expressly disclaim any warranty that the data are error-free or current as of the date supplied
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