Excerpts from the report: The Gunnison River Basin is located in West-Central Colorado. Its boundary encompasses an area of 8,020 square miles and includes all or major portions of Gunnison, Montrose, Delta and Ouray Counties and portions of Mesa, Hinsdale, Saguache and San Juan Counties. The Continental Divide forms the east and southeast boundary of the Basin and the San Juan Mountains and Uncompahgre Plateau form the south and southwest boundary. The Basin is bounded on the north by the Elk Mountains and the Grand Mesa and on the northwest by the Grand Valley. It is approximately 145 miles long east and west and 95 miles wide at its widest point north and south. The Gunnison River and its tributaries drain about 8 percent of the area of the State of Colorado. This report presents information concerning water and related land resources of the Gunnison River Basin in Colorado. This is a report of a reconnaissance study. The information presented for the Gunnison River Basin is prepared for the Basin as a unit and for each of the five major subbasins. These subbasins were delineated because of the nature of their individual water and related land resources. The subbasins are shown on the attached map and are identified as follows: Upper Gunnison, Smith Fork-Crystal, North Fork, Uncompahgre and Whitewater.