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WILDLIFE RESOURCES ASSESSMENT DUCKWORTH PIT, WELD COUNTY, COLORADO processing at existing gravel processing facilities south of the road. Mining of the gravel resources will completely avoid Idaho Creek and any associated wetlands. Water within Idaho Creek is fully controlled by a headgate located upstream on Boulder Creek and the creek functions entirely as a controlled irrigation canal. The excavated azeas reclaimed as two recreational, groundwater ponds. Ecological and Other Features of the Assessment Area The project site is located between Highways 119 and 52, just west of Rinn in Weld County, Colorado (Figure 1). This site historically has been used for agriculture, including livestock grazing and agricultural crops. Idaho Creek has been greatly altered by channelization, water diversion, and bank stabilization (riprap banks) and presently functions entirely as an irrigation canal. Land use in the azea consists of agriculture, sand and gravel mining, light industrial and rural residential. Portions of the Idaho Creek corridor have been impacted by past agricultural practices and aggregate mining, both upstream and downstream of the site. Rural residential homes have been built immediately north of the project site (Photograph 1). The western side of the project site contains a mowed hay field composed of pasture grasses (Photograph 2). Native vegetation in this area has been largely replaced by introduced grasses such smooth brome (Bromopsis inermis), slender wheatgrass (Agropyron elongatum), and Kentucky bluegrass (Poa pretensis). The eastern side of the project site is a grazed pasture characterized by a mixture of native and introduced grasses. The entire pasture has been grazed by livestock and a small colony of prairie dogs. The grass cover within the pasture is very dense and contains generally less than 5 percent baze ground. Idaho Creek is chazacterized as a small meandering irrigation canal with a narrow band of wet meadow and wetland vegetation (Photographs 3 and 4 taken in 2003). Vegetation along the creek consists of a vaziety of wetland species including reed canarygrass (Phalaris arundinacea), wooly sedge (Carex lanuginosa), curly dock (Rumex crispus), and cordgrass (Spartina pectinata). The creek contains very little shrub cover, although patches of low growing sandbar willow (Salix exigua) are scattered along the creek. Water flow through Idaho Creek is entirely diverted out of Boulder Creek and the ERO Resourres Corpomfion