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I I I I I I I I I I I I I I I I I I I through Grand Staircase Escalante National Monument and Glen Canyon National Recreation Area. An excellent discription of the physical attributes of the drainage is presented in Ottenbacher and Hepworth (1999). The stream is relatively small but flows are higWy erratic do to spring run-off and flash flooding during the summer monsoon season (Appendix A). Low base flows that are aggravated by irrigation diversions. The furthest downstream gauging station (#09337500) is located near the town of Escalante, Utah, which is relatively high in the water shed. Additional base and storm flows are contributed to the river by tributaries or side canyons such as: Boulder Creek, Harris Wash, Silver Falls Creek, Twenty-five Mile Wash, Moody Canyon, Stevens Canyon, and Coyote Gulch. Sampling was conducted in two sections of the river's lower 80 Ians which provided access and extraction by helicopter or by boat. This was necessary do to the absence of roads. The upstream section was located between Harris Wash and Fence Canyon (10 Ian). The survey team was dropped off at Harris Wash and backpacked downstream sampling and photographing four sites located at 3 km intervals (Map 1 & Appendix A). Here the canyon floor is relatively broad and the stream meanders through a well developed riparian corridor composed of willow, cottonwood, and tamarisk. Stream habitat is dominated by run and riffle habitat as it drops an average of 3.2 mIkm. Stream bank undercutting and riparian vegetation in some areas provide overhead cover and diverified habitat for aquatic animals. Deep pools or backwaters were rare or absent. The stream bed was composed primarily of sands and gravels. Fence Canyon had several small, entrenched pools, that were formed by rock depressions and clay. One was sampled that was located approximately 100 m upstream of the Canyon's confluence with the river. Sampling in the lower most river reach was completed between Fool's Canyon and Coyote Gulch (Map 1). In this area the river enters a narrow canyon. Stream gradient decreases (2.1 mIkm) and the stream bed and banks are littered with rock rubble and large (>4 m) boulders. Fine sands replace gravels as the predominate substrate size and riparian vegetation is restricted to colonizing tamarisk and willow. Cover is limited to washouts formed around large boulders and rock rubble. Another changes occurs further downstream at Steven's Canyon where the number oflarge bounders diminish and the stream bed becomes broader and shallower. The substrate is dominated by sands and fine gravels and there are narrow stands of dense willow and tamarisk. Sediment deposition is obvious not only in the mainstem river but also up Coyote Gulch. It's believed sediment loading is influenced by reservoir elevations. Again, sampling was conducted at 3 Ian intervals in this 10 Ian reach. 2