The supplementation of natural populations of Pacific salmon Oncorhynchus spp. with hatchery fish poses unique management challenges. Two such challenges addressed in this study are limiting the number of hatchery fish spawning with natural‐origin fish and maximizing the number of natural‐origin fish in the supplementation broodstock. In this study, we focus on stock enhancement of Sockeye Salmon O. nerka in Hidden Lake, Alaska, where the Trail Lakes Hatchery supplements the natural population with hatchery‐raised fry. Production in Hidden Lake is limited by the availability of spawning habitat and not by juvenile rearing capacity. The hatchery collects broodstock from the lake and releases fry with thermally marked otoliths at one of two primary natural spawning sites in Hidden Lake each year. During this study, an average of 58% of the fish returning to the lake through a weir on the outlet stream were of hatchery origin. However, an average of 88% of the fish at the release site were hatchery‐origin fish, indicating a nonrandom distribution of hatchery‐origin spawners. This pattern is consistent with homing to specific sites within the lake of either or both hatchery‐ and wild‐origin fish. However, this distribution results in a larger‐than‐desirable proportion of hatchery‐origin fish spawning with natural‐origin fish at the release site. The proportion of hatchery‐origin fish used for brood is also larger than desirable because the site is also the broodstock collection site. We propose that releasing hatchery fish at a new location removed from the primary spawning areas and the hatchery broodstock collection site will reduce the proportion of hatchery‐origin fish spawning with wild‐origin fish and increase the proportion of wild‐origin fish in the broodstock, if our results are due, at least in part, to homing of hatchery fish. Received May 12, 2012; accepted May 20, 2013

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