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Description of the Study Area Boundary and Location The Dallas Creek Project lies almost wholly within Ouray County' in southwestern Colorado. It is near the headwaters of the Uncompahgre River which forms on the steep slopes of the San Juan Mountains at elevations exceeding 14,000 feet. Elevations drop to approximately'" 7,000 feet at the town of Ri,:lgway and approximately 6,300 feet in the ' Uncompahgre River Valley at the Ouray-Montrose County line, ' Dallas, Creek and tributaries form the major drainage area to the west, while' Cow Creek drains the area to the east. In addition to Ouray County, the study area includes Montrose City and 01athe town in Montrose County, and Delta City in Delta County, 29, 41, and 54 river miles respectively from the proposed Ridgway Reservoir. S '1 (1) 01. s Five major soil groupings are recognized in the study area. They consist of (1), Desert SierozeR; (2) Brown-chestnut; (3) Mountain Prairie-chestnut; (4) Gray wooded-Brown-Podzo1ic~Mountain Prairie; and (5) Alpine Meadow-Alpine Bog. Irrigated acreages in Ouray County occur primarily on groups 2 and 3. The soils in the stream valleys are generally heavier textured soils both from shale and sandstone, while the soils in the Log Hill Mesa area generally are lighter textured from sandstone. Internal soil drainage is a problem on most of the heaVYj clay loam soils of the bottom1ands where heavy seepage at the upland edges occurs. The proposed irrigation of new lands in the Log Ui11 Mesa area may require protective surface and internal drainage measures to control sediment loading and seepage. (2) Climate The climate of the study area is highly influenced by the San Juan Mountains. Temperatures are more severe in the high, rugged mountains to the south and comparatively mild to the north. January o 0 temperatures average about 28 F and the July average is about 65 F. Annual precipitation averages about 20 inches ranging from less than 10 inches in the north portion to about 40 inches in the south portion. The annual frost-free period in Ouray County averages about 128 days. Transportation and Utilities .' ;1 :! The study area is isolated from large populated areas such as Denver on the eastern slope at a distance of about 275 miles, and Salt Lake City to the west about 300 miles. U. S. Highway No. 550 traverses the study area, generally following the Uncompahgre River Valley and leaves the area's southern boundary at Red Mountain Pass sUlllDlit. Approximately twelve local and interstate truck lines provide 7