Three Island Lake is not individually listed in the Region 4 synopsis, so the regional stillwater default applies: trout/char daily quota 5, no more than 1 rainbow or cutthroat over 50 cm. A freshwater licence is required for anglers 16 and over. Confirm the current synopsis before you fish.

The lake covers 23.7 hectares. A 1991 provincial fisheries investigation found a maximum depth of 34.3 m and a mean depth of 10.7 m, with a Secchi clarity of 6.5 m and an alkaline surface pH of 9.5. That is a lot of depth for a lake this size, and it means real shoal-and-drop-off structure rather than a shallow bowl: the three islands that give the lake its name sit over the shallower shelf, with the basin dropping away fast beyond them.

Three Island fishes as a put-grow stillwater: the rainbow trout go in as small yearlings and grow on the lake's natural forage, so the fish in the net any given season are one or more years removed from the truck. Work a chironomid under an indicator over the shoal around the islands, and switch to a balanced leech or Woolly Bugger worked slow along the drop-offs once the shallows warm through summer. Dragonfly and damselfly nymph patterns stripped toward shore are worth a look in a lake this deep and clear, though no local report has confirmed the hatch timing here. The stocking record below is the closest thing to a fishing report this lake has.

No confirmed public launch, trailhead or parking area has turned up for Three Island Lake. The lake sits south of the Spillimacheen River and southeast of Golden, between the Spillimacheen and Bobbie Burns Creek drainages. Confirm the access road and any seasonal restrictions locally before planning a trip.

Three Island Lake is a rainbow-only put-and-take fishery: 65 recorded releases since 1959, missing only a handful of years, totalling roughly 331,000 rainbow trout. In recent years the program has settled to 1,000 Pennask-strain yearlings released each spring from the Beaver hatchery. The full year-by-year release history is below.