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INTRODUCTION AND METHODS This report presents the results of our original field studies of the physical, chemical and biological characteristics of selected wetlands at the Ouray National Wildlife Refuge, near Vernal, Utah. All field work was conducted between June and September 1993. This study area was the largest and most difficult of the four major study sites to work in. Access to land on the east side of the Green River was difficult, there was an incredible plague of mosquitos during the summer, thickets of tamarisk and other plants made travel difficult and there were vast areas of standing water. Much of our work focuses on Old Charlie Wash (Woods Pool) and Wyasket Lake on the east side of the Green River, and wetlands in and near Leota Bottom and Sheppard Bottom on the west side of the River. Wyasket Lake was accessible only by canoeing across the river, portaging several hundred yards across the floodplain and then canoeing again into the lake. Old Charlie could be reached by automobile. The goals of this baseline study was to determine how the wetlands function at present, and the possibilities of using these wetlands for razorback sucker habitat. Our study goals for the Ouray National Wildlife Refuge were different from our goals at the other three major study sites previously presented (Cooper and Severn 1993, 1994a, 1994b) because access was difficult. Here we focused primarily on the water levels and invertebrate biomass relationships of Old Charlie Wash and Wyasket Lake in comparison with the Green River, backwaters of the Green River, and the man-made marshes at Leota Bottom. For our hydrologic studies we established 13 staff gauges in water bodies on site and also installed 5 ground water monitoring wells. Wells were constructed of 1 inch PVC pipe which were placed into hand augured holes that reached the water table. Our goal was to establish wells which would allow us to determine the depth to water table through our sample period. Machine slotted PVC pipe was used in the lower portion of the well and unslotted PVC pipe in the upper part. The well was capped on the bottom and top ends and depth to water table was determined with a well- reader. Surface and ground water levels were recorded regularly during the sample period. Data on Green River stage is correlated with water levels in the wetlands to determine whether river and wetlands were hydrologically connected or whether the wetlands are fed largely by other water sources. The wells and staff gauges also helped us to determine the duration of inundation in wetlands. Physical and chemical characteristics of water at staff gauges (surface waters) and in wells (groundwater) were determined in the field and laboratory. We determined pH, 1