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e were that the flow from the cliff was coincident with flows in West Dead Horse Creek. It is possible that there are other contributing sources within the lower watershed to this flow. This flowline was created and is most likely maintained during peak snowmelt runoff contributions to streamflow (Kuyurnjian, 1996). The guide describes a depression above the seventh bridge that drains water into an underground stream. Drainage to this depression is from West Dead Horse Creek. Water flowed to this point during snowmelt runoff in 1996. Only a small percentage of the water makes it past this point to the confluence with East Dead Horse Creek. This drain may be the source to the spring described above. D. Geology The geology of the lower Dead Horse Creek watershed is characterized by steep canyons. The area can be described as having typical "karst topography", or "a type of topography that is formed over limestone, dolomite, or gypsum by dissolving or solutions, and that is characterized by closed depressions or sinkholes, caves, and underground drainage (American Geological Institute, 1972)". The geology of the Dead Horse Creek watershed, as mapped by Kirkham et al. (1995) is shown in Figure 4. The Grizzly Creek Fault crosses the watershed. The geologic unit mapped at Hanging Lake is described as: Qtu: tufa (Holocene and Pleistocene?)- Low density, porous chemical sedimentary rocks consisting of calcium carbonate precipitated from mineral-charged spring, ground, and surface water. Occurs as massive ledges and as a gravel-cementing material in Dead Horse Creek. Appears to have created the dam behind which Hanging Lake has fonned. Maximum thickness probably 30 to 40 feet. This also describes parts of the Dead Horse Creek and East Dead Horse Creek channels. Other geologic units in the Dead Horse Creek drainage mapped by Kirkham et al. (1995) are: Qt: Talus (Holocene and late Pleistocene)--derived from bedrock outcrops upslope Qac: Alluvium and colluvium, undivided (Holocene and late Pleistocene)-- sediments deposited by alluvial and colluvial processes MI: Leadville Limestone (Mississippian)-- this unit is rnapped in the upper portions of the watershed Dc: Chaffee Group (Upper Devonian)--consists of shale, quartzite, dolomite, limestone, and dolomitic sandstone Om: Manitou Formation (Lower Ordovician)-- consists of dolomite with thin beds oflimestone, shale, and sandstone Cd: Dotsero Formation (Upper Cambrian)--consists of dolomite, dolomitic sandstone, dolomitic shale, limestone and dolomite conglomerate, limestone, and algal limestone. e A more detailed geologic report is presented in Appendix H. e 6