In 1995 and 1996, 110 adult Arctic grayling Thymallus arcticus with implanted radio transmitters were released at their summer feeding area in the Delta Clearwater River, a spring-fed tributary to the Tanana River in interior Alaska. The fish were tracked from aircraft and by boat for one year after implanting to locate overwintering and spawning areas and to estimate fidelity to the Delta Clearwater River for summer feeding. The majority of fish overwintered within a 115 mi reach of the Tanana River. Spawning areas were found in eight streams up to 72 mi distant from release. The greatest proportion of radio tagged fish spawned in the Goodpaster (59%, SE = 7%) and Volkmar (20%, SE = 6%) rivers. After spawning, 98% (SE = 3%) of live fish returned to the Delta Clearwater River for summer feeding. A radio tag shedding rate of 25% (SE = 9%) is estimated from recaptures of 24 radio-tagged fish one to two years after release.