OCR Text |
Show 40 rains of cloudburst proportions typical of the summer season in semiarid regions can wash out or bury roads quickly and otherwise make general travel difficult. The winters are usually dry and hence much snow does not accumulate in the valleys. On the Dolores Plateau south of the Slickrock area, where elevations are around 7,000 feet, considerably more snow falls. On the Uncompahgre Plateau at about 9,500 feet altitude much snow accumulates, tut along the road through Unaweep Canyon, 2,000 to 2,500 feet lower, snow seldom interfers with highway travel. Topography The great diversity of land forms is the cause for the irregular boundary shown on the accompanying series of twelve maps (PV-225, 1-12) indicating areas underlain by vanadium-bearing formations in Southwestern Colorado. It was not feasible to add contours on the maps; therefore, a brief summary of the topography may be helpful in obtaining a better understanding of the boundaries of these formations as shown on the maps. The area under consideration is characterized by (l) numerous steep-walled canyons of the Dolores River and its tributaries; (2) wide valleys such as Paradox, Gypsum, Sinbad, Dry Creek and Disappointment valleys that represent erosion along anticlines and synclines; and (3) extensive, high, flat areas such as the Uncompahgre Plateau to the north, |