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above the water when mounted on a boat, or mounted directly to an air- plane wing strut. The loop antenna (directional) was used only to tri- angulate fish location by boat or from shore. It was necessary to use aircraft to keep contact with several fish at one time. The most successful aircraft used were a helicopter and a Piper Supercub. The aircraft were operated as slow as practicable at low elevation. The radiotelemetry program utilized two different methods for recording information about habitat preferences and movement. Long distance movement was determined by attempting to locate all radiotagged fish during a one to two day interval. (The location of a fish was recorded on a one-time basis when encountered). In order to obtain more specific information on movement and habitat preferences, a diel sampling procedure was employed which consisted of observations made continuously over a 24h basis as follows: F 1. The day was divided into three, eight-hour periods and one selected at random. A fish was then observed during this period, with depth, velocity and substrate determinations made every 15 minutes. Habitat measurements were not recorded unless fish were stationary for 30 minutes. 2. After a fish had been monitored for three, eight-hour periods, the fish with the next tag number was then selected for study. Data Storage and Retrieval The MANAGE data base management system developed by the Western Energy and Land Use Team (WELUT) in Fort Collins, Colorado was used for the project. This system provided storage, retrieval and manipulation of large volumes of data. In addition, data analysis capability was integrated into the MANAGE system by integrating certain features of the IMSL (International Mathematical and Statistical Library) Package (Shumate et al. 1981). Field data were organized into four data sets in the Vernal data base. Data sheets and the following data sets were developed: 1. PHYSICAL: Physical and chemical data, including water and air temperature, dissolved oxygen, conductivity, salinity, turbidity, and stream width and depth. 2. CATCH: Catch data for fishes; included sample time, duration, gear type, habitat, area sampled, depth, velocity, and substrate for each fish species (endangered and non-en- dangered) by age groups. 3. RARE: Included sample time, duration, gear type, habitat _ area sampled, depth, velocity, substrate type, sex, length, weight, tag size and number, and macroscopic external parasite load for each endangered or threatened fish captured. 15.