The stocking record tells two separate stories, seventy years apart. Between 1923 and 1954, the province planted wild-origin rainbow trout fry five times, 30,725 fish in total, drawn from four different hatchery source strains (Gerrard Creek, Pennask, Pinantan and Loon Creek). That program ended in 1954 and did not resume. Then, starting in 1988, the lake was stocked six more times with wild-origin, Connor-strain
westslope cutthroat trout fall fry, 17,000 fish in total, the last release 2,000 fish on 1996-09-30. The Connor strain is the genetically pure westslope cutthroat broodstock line used widely across East Kootenay stillwaters. Nothing has been logged since 1996, so whatever is swimming in Island Lake today is a holdover or naturally reproducing fish, not a recent plant.