A small stillwater south of Ainsworth on the west side of Kootenay Lake, about 8.7 hectares and 9 metres at its deepest. A century of stocking has cycled through brook trout, rainbow trout and kokanee, and today the lake runs on an annual mid-June plant of Pennask rainbow yearlings alongside kokanee fry.

Loon Lake sits south of Ainsworth on the west side of Kootenay Lake, in the Kootenay Lake watershed. The province's 1971 survey puts it at 8.7 hectares, dropping to a maximum depth of 9.1 m and averaging 4.5 m across the basin, a small, shallow-to-moderate stillwater rather than a deep, sharply stratified one.

For an angler judging whether the lake is worth a stop, the release record is the fishing report. Provincial hatchery records run from 1924 to 2026 and log 69 releases into Loon Lake, totalling roughly 577,000 fish. The bulk of that volume is historical: brook trout alone account for about 516,500 fish over 33 releases between 1924 and 1976, but the program stopped there and hasn't resumed since. Rainbow trout have the longest continuous record, stocked on and off since 1958 and most recently in June 2026 (Pennask-strain yearlings, 800 fish), for a total of about 54,400 fish over 27 releases.

Kokanee are the newer annual program: nine releases since 2017, most recently 800 Norbury Creek-strain fry in June 2026, following a similar mid-June plant of Pennask rainbow yearlings the same day. That pairing (rainbow and kokanee, same day, same 800-fish quantity) has repeated every year since 2024, making them the freshest, most reliable cohorts in the lake today, while any brook trout you catch are legacy fish from a program closed exactly half a century ago, not a recent plant.

Loon Lake fishes as a straightforward small stillwater: work the shoal-and-drop-off structure around the edges rather than the deep middle of its 9 m basin. Hang a chironomid or scud pattern under an indicator over the shoals (chironomid under indicator is the standard rig) for the rainbow, then switch to a woolly bugger or balanced leech on a sinking line along the drop-off as the shallows warm. Kokanee key on zooplankton rather than the shoal forage, so they are best covered by trolling small spoons or flies over deeper water rather than sight-fishing the edges.

No confirmed boat launch, parking area or shoreline access point has been found for Loon Lake; it sits in the hills west of Kootenay Lake near Ainsworth Hot Springs. Treat this as an access-check water: confirm a put-in and any private-land or seasonal restrictions locally before committing a day to it.