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1. Fish to be studied were selected by tag number from a table of random digits. 2. The day was divided into three eight-hour periods and one selected at random. A fish was then observed during this period. If a fish remained stationary for 30 minutes, then water depth, water velocity and substrate determinations were made at 15 minute intervals. 3. After a fish had been monitored for three, eight-hour, periods, the fish with the next tag number was then selected for study. The location of each radiotelemetered fish was carefully fixed and recorded. General location was recorded in river miles (RM) upstream of the mouth of each river, as given in Belknap and Belknap (197 and Evans and Belknap (1973), and converted into river kilometers (RK) later. If the fish remained in one location for 30 minutes it was assumed this habitat was preferred and microhabitat information was recorded, including the general habitat, substrate type, water depth and water velocity. Water depth, velocity and substrate measurements were taken only when the fish moved to another location or at the end of the study period. These precautions were taken in order to minimize disturbance to the fish. Water depth was recorded by direct measurement with a wading rod and water velocity was measured 0.6 of the distance from the water surface with a Marsh-McBirney current meter. Substrate type was obtained by direct observation and by probing with a wading rod. The MANAGE data based management system developed by the FWS Western Energy and Land Use Team (WELUT) in Fort Collins, Colorado was used for storage, retrieval and manipulation of the data (Shumate et al. 1981). Field data were organized into four data sets; PHYSICAL, CATCH, RARE and RADIO. The following two data sets were used in this report: RARE: Included sample time, duration, gear type, habitat area sampled, water depth, water velocity, substrate type, sex, length, weight, tag size and number for each endangered fish captured. RADIO: Movement data for radiotagged fish included observation ti- me,-distances of movement, type of movement, water depth, water velocity and substrate of preferred habitat, water flow and temp erature. Because the MANAGE program accepts alphanumeric codes fish species and other observations were coded on the data sheets as letters rather than numerals. As an example, the substrate "sand" was coded as "SA" which facilitated field recording. Numeric information was entered directly. 5