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• 2.04.5 GENERAL DESCRIPTION OF HYDROLOGY AND GEOLOGY General Geology Phvsiogra~hv. WFC's New Horizon Mine is located two and one-half miles northwest of Nucla in Montrose County, Colorado. The mine is located v~ithin the Colorado Plateau Physiographic Province, Canyon Land section in southwest Colorado. The region is characterized by broad, fairly smooth surfaced plateaus and mesas v~ith gently dipping slopes dissected by deep canyons. Numerous large folds and rugged laccolithic mountains attribute their topographic relief and steep slopes to geologic structures; while local hills, drains, and canyons are erosional features produced by surface drainage. In relation to regional drainage systems, the permit area is located in the upper reaches of Tuttle draw, a tributary to the San Miguel River. The San Miguel River empties into the Dolores River • northeast of Uravan, Colorado, which in tum, leaves the state northwest of Gateway, Colorado and empties into the upper Colorado River in Utah. Approximately 4,870 feet of relief is present in the Nucla area, from a high elevation of 9,870 feet (MSL) at the crest of the Uncompahgre Plateau to the northeast, to below 5,000 feet (MSL) along the San Miguel River at Uravan. Steep slopes are comrnon on the flanks of the Uncompahgre Plateau; whereas more gentle slopes dominate in the Nucla area. Vertical drops of several hundred feet are not uncommon along the San Miguel and Dolores River canyons. mine range from a high of 5,767 feet (MSL) in the northwest part of the permit, to a low of slightly less than 5,672 feet (MSL) in the southeast part along Tuttle Draw (see Map 2.04.7-1). Total topographic relief for the permit area is 95 feet (MSL). Topographic features on the permit include gentle southwest facing slopes, low rolling hills, old spoil piles, regraded mined areas cut by open pits, and shallow drains (euphemeral) which feed Tuttle Draw (intermittent). 2.04.5 - 1