Northwestern Colorado contains the largest reserves of shale oil in the world and the coal beds of the area are some of the most extensive in the United States. Development of the oil shale and coal may require large supplies of water and may therefore create additional demands on the surface-water resources of the region. The availability of ground water, however, is not well known. The Eocene Green River Formation in the Piceance basin has been estimated to contain several million acre-ft of ground water that generally is chemically suitable for most uses, and the ground-water resources of all northwestern Colorado probably are much larger.

Preliminary studies indicate that large quantities of water may be available in the Mississippian Leadville Limestone on the southern, western, and northern flanks of the White River Uplift. The Leadville is about 200 ft (6 m) thick, has solution openings, and is very permeable at least in places. Much of this permeability, as evidenced by the extensive paleokarst topography throughout most of western Colorado, had developed by the beginning of the Pennsylvanian Period. The Leadville yields water to at least 100 springs and probably forms a major aquifer system that would yield calcium carbonate type water to shallow wells on the flanks of the White River Uplift. The quantity of ground water in storage in the Leadville Limestone in the western one-half of the White River Uplift area m y exceed 10 million acre-ft. Exploratory drilling and testing of the Leadville Limestone to depths of 2,000 ft (600 m) are needed to evaluate the potential of this aquifer for providing large supplies of water.

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