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The project area is located at the south-west portion of the Axial Fold Belt, a major <br />geologic feature of western Colorado. The Axial Basin anticline (or uplift) is a relatively <br />low arch standing between The Uinta Mountains to the north and the White River uplift to <br />the south. It separates the Sand Wash Basin on the east from the Piceance Creek Basin on <br />its southwest. Regional uplift occurred in the Late Tertiary, and erosion of the area has <br />removed most of the Tertiary rocks. Well known anticlines in the region include Blue <br />Mountain, Cross Mountain, and Danforth Hills. Geologically, it began to rise during the <br />Paleocene and separated the Green River Basin into two parts. Its upward movement was <br />reactivated during the Tertiary and since then most of the Tertiary-age rocks have been <br />eroded away (Young and Young 1977: 57). Within the study area the Cretaceous-age <br />sedimentary rocks including sandstones and shales along with major coal beds of the <br />Williams Fork Formation form the bedrock. <br />The study unit lies within the Williams Fork Mountains, which form the divide <br />between the Yampa River Valley to the north and the Williams Fork Valley to the south. <br />Buck Peak lies to the northeast. These mountains are heavily dissected by tributary <br />drainages that flow northeast to the Yampa River and southwest to the Williams Fork River. <br />Permanent and intermittent drainages occurring near or within the project area include <br />Jeffway Gulch, Deal Gulch and Spring Gulch, which drain into the Williams Fork River to <br />the south, and Deacon Gulch, which drains into the Yampa River to the north. The <br />headwaters of many of these are fed by unnamed springs located throughout the study area. <br />Area 1, to the northeast contains three types of soil. The most predominate two are <br />Forelle-Evanot complex, 12 to 25 percent slopes and Kemmerer-Moyerson complex, 20 to <br />40 percent slopes. Forelle-Evanot complex is found on hillslopes and is mostly loam to clay <br />loam whose parent material is loess. Kemmerer-Moyerson complex, found on hills, <br />consists of silty clay loams whose parent material is residuum derived from shale. Lesser <br />amounts of Battlement fine sandy loam, 0 to 3 percent slope is present as well. <br />Area 2, to the west consist of primarily of Evanot loam, 1 to 12 percent slopes. This <br />loamy soil type is found on hillslopes and structural benches and is formed from a parent <br />material of loess. Lesser amounts of Evanot loam, 12 to 25 percent slopes and Moyerson- <br />Rentsac complex (silty clay loams), 15 to 45 percent slopes are also present. All are well <br />drained with high runoff (USDA NRCS website accessed 4/27/2023). <br />Elevations within the project area range from approximately 6320 to 6440 feet. fall <br />within the Upper Sonoran zone. Sage shrubland is the dominant plant community. <br />Sagebrush communities naturally occur in open parks and the drainage bottoms areas and in <br />on the bench tops and talus slopes. Big sagebrush (Artemisia tridentata) dominates this <br />plant community. Other shrubs present include saltbush (Atriplex canescens), shadscale <br />(Atriplex confertifolia), rabbitbrush (Chrysothamnus nausoesus), mountain mahogany <br />(Cercocarpus montanus), bitterbrush (Purshia tridentata), winterfat (Eurotia lanata), and, <br />where soils are more saline, greasewood (Sarcobatus vermiculatus). Prickly pear (Opuntia <br />sp.) is common. Among the grasses found here are cheat (Bromus tectorum), western wheat <br />2