Not individually listed in the Region 4 synopsis, so the general provincial and Region 4 (Kootenay) rules apply. Confirm the current synopsis before you fish.

Siwash Lake sits in the hills southwest of Nelson, on the west side of the Kootenay Lake drainage. It covers 7.8 hectares, small enough to fish thoroughly from a float tube or small boat in a day. No provincial depth survey is on file for this lake, so its bathymetry and shoal structure are unconfirmed; treat any drop-off you find on the water as the working structure until it is mapped.

Siwash carries a single species record, rainbow trout, and every one of the 31 recorded catch observations on file is that species. Treat it as a small put-grow stillwater: work a chironomid under an indicator over any shoal or drop-off you can find, and fall back on a slow-stripped leech pattern such as a Woolly Bugger or balanced leech along the shoreline edges. With the release program lapsed since 2012, whatever rainbow trout remain are a residual, naturally reproducing population rather than fresh-planted catchables, so numbers and average size are both unconfirmed.

Siwash Lake's launch, parking and any walk-in or seasonal access limits are not yet confirmed; the map panel shows where the lake sits southwest of Nelson.

For an angler judging whether the fishing is worth the trip, the release record is the honest answer: Siwash Lake ran as a put-and-take rainbow trout fishery for almost three decades, 30 recorded releases totalling about 57,250 fish between 1983 and 2012, drawing mostly on Pennask and Premier strains through the Beaver hatchery. Nothing has been released since 2012, so the program appears to have wound down rather than paused. The full year-by-year release history is below.