The fish populations of the Athabasca River between Fort McMurray and the mouth of the Firebag River were sampled from early May to early October 1976. Fish were collected with gill nets, seines, and angling gear in order to identify the species present and their distribution and relative abundance over time, and to obtain samples for life history analysis. A tagging program was undertaken to delineate migration patterns for the major fish species. Results indicate the presence of 25 fish species within the study area, 11 of which are common. Major spawning migrations of walleye, longnose suckers, and white suckers enter the study area in early spring and a large spawning run of lake whitefish occurs in late summer. The entire study area appears to be important as a summer feeding area for immature goldeye. These goldeye, which may belong to the population that spawns in the Peace-Athabasca Delta, enter the study area in early spring and apparently leave in late fall. Trout-perch, flathead chub, lake chub, and emerald shiners are the major forage fishes occurring within the study area. Floy tags were applied to 2528 fish and the recapture rate to date is 2%. Preliminary tag return data indicate some movement of suckers, goldeye, lake whitefish, and walleye between the study area and Lake Athabasca. The fry of many fish species appear in the Athabasca River during June and July. Most of these fry do not remain in the study area but are carried downstream to nursery areas in the lower Athabasca River or Lake Athabasca.