Laserfiche WebLink
NQ LA- e F ?rtJ et a/. <br />Oeo C 74 <br />RESOURCE MANAGEMENT CONSIDERATIONS IN A CHANGING PHYSICAL <br />ENVIRONMENT: THE GUNNISON GORGE, COLORADO <br />John G. Elliott', Dennis M. Murphy2, and Karen S. Tucker3 <br />ABSTRACT: The U.S. Bureau of Land Management administers the Gunnison Gorge and <br />places a high priority on protecting the area's unique natural resources and providing <br />opportunities for wilderness recreation. A U.S. Geological Survey study indicated that <br />streamflow regulation since 1966 has decreased bed-material movement and flood levels in <br />the Gunnison Gorge; however, large volumes of sediment continue to be supplied by <br />unregulated tributary canyons. This change in streamflow regime has affected the channel <br />geometry, fish habitat, vegetation distribution, and recreational use of the area. Visitor use <br />is increasing and demands on the natural resources are strongly related to hydrograph <br />characteristics. Low flows (less than 30 m3/s) favor fishermen who hike into the Gunnison <br />Gorge and wade the river. Higher flows (greater than 85 m3/s) favor whitewater boaters <br />and fishermen who raft to fishing areas. Flows between 30 and 85 m3/s provide optimal <br />conditions for the greatest number of users; however, high-use in this range poses the <br />greatest threat to wilderness values of the area. Continually evolving physical and <br />biological characteristics, annual and seasonal streamflow uncertainty, and changing visitor <br />demands complicate management decisions. Hydrologic, geomorphic, and biologic <br />research provides management agencies with information to better administer natural- <br />resource areas like the Gunnison Gorge. <br />KEY TERMS: Resource management, geomorphology, sediment mobility, riparian <br />conditions, recreation. <br />INTRODUCTION <br />The U.S. Bureau of Land Management (BLM) administers, and has recommended for <br />designation as a National Conservation Area, 260 km2 of land contiguous to the Black <br />Canyon of the Gunnison National Monument (BLCA) near Montrose, Colorado. Within this <br />area, the BLM has proposed the 90-km2 Gunnison Gorge Wilderness Study Area. The lower <br />1 Hydrologist, U.S. Geological Survey, Box 25046, MS 415, Denver, CO 80225 <br />2 Hydrologist, U.S. Bureau of Land Management, 2465 S. Townsend Ave., Montrose, CO <br />81401 <br />3 Outdoor Recreation Planner, U.S. Bureau of Land Management, 2505 S. Townsend Ave., <br />Montrose, CO 81401