Page:Land Protection Plan - Wyoming Toad Conservation Area.pdf/18

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 * 8Land Protection Plan—Wyoming Toad Conservation Area, Wyoming
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The physiography of the Laramie Plains has been influenced by shallow, warm sea water; a crustal uplift that affected Colorado and southeastern Wyoming; the Laramie Orogeny Mountain building episode; volcanic activity in the Yellowstone area; and ice ages. Most of the stable landforms in the area were created within the last 100,000 years by glacial outwash waters. Many of the valley soils are rather deep and alluvial in nature, having been derived from the surrounding granitic mountains (USDA 1998). Soil texture near the mountains tends to be coarse, but it becomes progressively finer toward the basin center. The alluvial overburden is too thick to allow profitable petroleum development in most of the basin, although limited opportunities for such development do occur. The high, flat nature of much of eastern Wyoming is conducive to the development of strong winds, and several features on the land suggest that wind has played an important role in past geological development as well.

Sand and gravel are the major mineral commodities in the Laramie Plains. Sand and gravel mines are scattered throughout the basin, with the biggest concentration near the southern part. Other minerals that are mined in the area include shale, gold, gypsum, and limestone. The potential for oil and gas exploration within the basin is rated as moderate, with scattered high potential areas outside the project area to the north. There are no active coal mining permits in the Laramie Plains at this time (Wyoming Department of Environmental Quality 2014).

Over 82 miles of the Laramie River and a 41-milelong reach of the Little Laramie River flow through the proposed WTCA. The Laramie River’s headwaters are in the Rawah Mountain Range in Colorado (figure LPP-2), and the river itself ultimately empties into the North Platte River near Wheatland, Wyoming (USDA 1998). Smaller tributaries feed into the Laramie River from the Laramie Mountains to the east and the Medicine Bow Mountains to the west. The river is the primary source of water in the Laramie Plains. Because the open plains receive little precipitation, most surface and ground water is a result of snowpack runoff from the surrounding mountains. Historically, many of the natural wetlands were associated with riparian corridors and playa lakebeds. However, the number and area of natural wetlands in Wyoming have continued to decline, whereas the acreages of ponds and other human-created waterbodies have increased (Wyoming Joint Venture Steering Committee 2010). This holds true for the Laramie Plains as well. The Casper aquifer is an important water-bearing geological formation that underlies the entire Laramie Plains and supplies most of the drinking water for the city of Laramie and Albany County.

This section describes the plant communities in the project area and the animals that they support. Table LPP-2 shows the habitat types in the proposed WTCA.

Vegetation communities within the proposed project area vary with topography and range from wetlands (which are often alkaline or saline) and riparian areas to wide expanses of shortgrass prairie and shrubland (see figure LPP-3). This section also