The number of Arctic grayling Thymallus arcticus over 249 mm in FL was estimated at 1,379 fish (SE = 166) in a 48 km section of the Snake River. The density was 29 fish/km. Arctic grayling ranged from 210 to 485 mm in FL and from 2 to 12 years of age. In a 12 km section of the Pilgrim River, the estimated abundance of Arctic grayling greater than 269 mm in FL was 353 fish (SE = 77) or 29 fish/km. They ranged from 235 to 486 mm in FL and from 2 to 13 years of age. The majority of Arctic grayling (50 and 52%) were in the "preferred" Relative Stock Density category in the Snake and Pilgrim rivers, while "memorable" fish comprised 35% of the Snake River sample and 34% of the Pilgrim River sample. Sixty Arctic grayling were captured on the Eldorado River and injected with OTC for later recapture in order to validate aging techniques. Salmon Lake was sampled using variable mesh gillnets and baited hoop and minnow traps in order to assess species presence and catch per unit of effort. Although a total of 309 fish comprising nine species were captured, numbers of fish were insufficient to estimate proportions of occurrence. Based on this study, few fish appear to inhabit Salmon Lake in mid-July.