Spatial geologic data model for the Gunnison, Grand Mesa, Uncompahgre National Forests mineral resource assessment area, southwestern Colorado and digital data for the Leadville, Montrose, Durango, and Colorado parts of the Grand Junction, Moab, and Cortez 1° x 2° geologic maps - Day, W.; Green, G.N.; Knepper Jr., D.; Phillips, R. (Open-File Report, 1999)