No separate Idlewild Lake entry appears in the current Region 4 synopsis, so the regional stillwater defaults apply: trout/char daily quota 5 (no more than 1 rainbow or cutthroat over 50 cm), bass and yellow perch closed, and a freshwater licence is required for anglers 16 and over. Confirm the current synopsis before fishing.

The Joseph Creek Management Framework places Idlewild among the creek's eight mapped reaches between the mouth at the St. Mary River and its headwaters south of Cranbrook, naming Reach 6 "Idlewild Lake/Park" and referring to it elsewhere as Idlewild Reservoir. Reach 7, immediately upstream, holds Phillips Reservoir and is flagged for adjacent private land. No area or depth survey is on record for Idlewild itself, and the coordinate used here (49.49806, -115.72977) is the FIDQ fish-presence point, which lines up with the FFSBC stocking record rather than a shoreline survey.

Idlewild carries westslope cutthroat trout, rainbow trout and brook trout, all put there by the provincial stocking program rather than through natural recruitment. Provincial stocking records show 81 recorded releases between 1975 and 2025; the most recent, in spring 2025, was 1,500 yearling cutthroat trout of Connor strain. Because it is run as a put-and-take fishery rather than a put-grow lake with a year or two of growing room, most fish caught are close to the size they were released at, so the best trips follow soon after a spring or fall stocking truck rather than chasing large holdovers.

With no confirmed bathymetry, treat it as shallow, shoal-dominated water until proven otherwise: work a chironomid under an indicator or a small leech close to shore and along any drop-off you can find, the same small-lake stillwater approach that works across the region's other put-and-take lakes.

For an angler judging whether it is worth the drive, the release history below is the most reliable fishing report available for Idlewild. It has been stocked since 1975, most recently with westslope cutthroat trout in 2025.

Idlewild Lake sits within Idlewild Park in Cranbrook, but no confirmed boat launch, parking area or trail has been verified for this page; check current access with the City of Cranbrook before planning a trip. No separate Idlewild Lake entry appears in the current Region 4 (Kootenay) synopsis, so the regional stillwater defaults apply.