The mean stomach volumes for smaller fish (mean total length = 4.56 inches) were 0.130 ml and 0.125 ml for the South Branch and Main Stream, respectively. Total volumes for larger fish (mean total length = 8. 81 inches) averaged 0. 885 ml and 0. 768 ml for the South Branch and Main Stream, respectively. The major diet components for both rivers were Trichoptera, Ephemeroptera, Diptera, and Mollusca. Also, Main Stream fish ate an abundance of Isopoda.

There was a marked shift between the diet of younger and older fish. Small food items such as Ephemeroptera and Isopoda which were so important to smaller fish were replaced in the diet of larger fish by higher amounts of Mollusca, Decapoda, Odonata, and especially by more fish.

A great difference in diet was observed between different months. Total stomach volume and the volumes of Trichoptera, Isopoda, and Amphipoda were highest in the early part of the growing season, especially in May. In contrast to this were the volumes of Mollusca, which were highest late in the season.

South Branch trout were in better condition and grew faster than Main Stream trout. This difference probably resulted from the greater volume of food per individual trout of the South Branch. Because the population of trout per acre for the Main Stream was more than twice that of the South Branch, intense competition for food probably accounted for the lower volumes of food per fish observed for the Main Stream. The estimated total volume of food consumed per acre for the entire growing season was 133, 871.4 ml for the South Branch and 260, 580. 6 ml for the Main Stream.