A mark-recapture experiment was conducted along the lower 14 miles of the Delta Clearwater River over two weeks during the middle of July 1998 to estimate abundance and composition of Arctic grayling Thymallus arcticus. Hook and line methods using jigs, flies, and spinners as terminal gear captured 2,443 fish. Estimated abundance of Arctic grayling 240 mm FL was 5,570 fish (SE = 780). Quality sized and larger fish (270 mm FL) predominated. Age-5 fish are fully recruited to the sampling gear and prior years fisheries. Age-5 fish comprised 30% (SE 2%) of the population 240 mm FL while age-4 and 6 comprised 14% (SE = 2%) each. Jig marked fish had significantly lower capture probabilities than fly marked fish and therefore were excluded from the experiment. A positive bias of 8% resulted when jig marked fish were included in the experiment.