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acre-feet, which is less than 3% ofthe total volume of the average annual streamflow. The dam is primarily operated as a run-of-the-river project where discharges released from the dam equal the inflow to the reservoir. The reservoir is used primarily for recreation and supplies little to no water for irrigation. Just downstream from the dam, the White River enters a broad alluvial valley. For the next 15 miles, the river flows through a valley where bedrock outcrops on opposite valley sides are between 0.9 and 1.2 rm apart. The river's slope is 0.0014 (Figure A-4) as it cuts a meandering course between outcrops ofthe Cretaceous Mancos Shale on the north, and the Tertiary Unita formation on the south. Several oxbow lakes occur on the flood plain in the upstream and downstream portions of this reach, and mid- channel islands are spaced at approximately 0.6 rm intervals. The town ofRangely, Colorado is located at approximately the center of this reach. At approximately rm 81, 15 rm downstream from Taylor Draw Dam, the river cuts through the southwest flank of the Rangely anticline. The valley width narrows to between 0.25 and 0.5 rm and the channel's increased gradient is 0.0030, which is maintained for the next 3 rm. Between rm 72 and 36, the river passes through a canyon cut into the Green River formation. Valley widths range from 0.1 to 0.4 rm, and the overall slope is 0.0013. River gradient within this canyon is steepest between the Colorado state line and the confluence with Evacuation Creek at rkm 97. The river slope is 0.0022 and the channel crosses the Mahogany Ledge oil shale member of the Green River formation. Our detailed study site (Figure A5) lies just downstream from this steep subreach. The study site extends 0.5 rm upstream and 0.1 rm downstream from the U.S. Geological 7