Waterfowl use was recorded in 1965 and 1966 at different elevations of the Uinta Mountains, Utah, from spring thaw until fall freeze-up. Sixteen species were observed; mallard (Anas platyrhynchos), green-winged teal (A. crecca), pintail (A. acuta), and ring-necked duck (Aythya collaris) were the most abundant. Ninety-eight percent of the observed waterfowl were below 3,000 m. Waterfowl numbers were highest during migratory periods and lowest in the breeding season. Adult waterfowl were seen most often on natural catchment basins and beaver (Castor canadensis) ponds larger than 0.4 ha. Low-elevation wetlands ( 2,900 m) had little waterfowl food. Utilization of high mountain wetlands by spring migrants and breeders was dependent upon ice melt, whereas freeze-up did not seriously affect fall use. J. WILDL. MANAGE. 41(1):172-117 Few intensive studies are available on the ecology of waterfowl in mountainous areas, and early mountain explorers wrote only brief notes on waterfowl observations at high elevations. Frary (1954) conducted a waterfowl production study on the White River Plateau in Colorado, and Rutherford and Hays (Unpublished data) investigated waterfowl breeding in the mountains surrounding the San Luis Valley, Colorado. Mallard, green-winged teal, and shoveler (Anas clypeata) were noted by Pattie and Verbeek (1966) on Beartooth Plateau, Montana. Several studies on waterfowl use and productivity of wetlands below 1,800 m have been conducted in Utah, but none has been made on the extent to which waterfowl use high mountain wetlands in Utah, nor on the contribution they made to the waterfowl resources of that state. Objectives of this study were to investigate species composition and seasonal changes in abundance of waterfowl in a high mountain area; define the types, distribution, and use of different wetlands; and estimate waterfowl production in a high mountain habitat. We thank the personnel of the Utah State Division of Wildlife Resources and the U.S. Fish and Wildlife Service for their financial support of this study, the U.S. Forest Service and Soil Conservation Service personnel for their valuable assistance, and the many recreationists who reported waterfowl observations.