2026 regulation year
Lake Koocanusa 2026 — Montana Fishing Regulations
Montana statewide rules apply unless overridden below.
Last updated
Lake Koocanusa carries a special-regulation overlay on top of Montana's 2026 fishing rules. Verify the agency booklet before launching: in-season changes are not yet wired to this page.
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State-level special regulation
Bull trout CATCH-AND-RELEASE only with a Lake Koocanusa Bull Trout Catch Card in possession (one of only two MT bull-trout angling areas — anglers select EITHER Koocanusa OR Hungry Horse + South Fork Flathead); rainbow trout adipose-clipped fish under 22 in must be released; kokanee salmon 50 / day, 100 in possession; 90-mile Kootenai River reservoir on the MT/BC border behind Libby Dam
Source: Montana special-water list
Official source
Montana Fish, Wildlife & Parks (FWP) publishes the authoritative 2026 Montana fishing regulations. Special-regulation lakes and rivers are listed in the agency booklet — always verify before fishing.
Visit official Montana fishing regulations →
Emergency-order channel
In-season closures, slot-limit changes, and run-count-driven harvest pauses are posted to Montana Fish, Wildlife & Parks's emergency-order feed — check it before any Montana trip during the active season.
Other special-regulation waters in Montana
Frequently asked questions
- What special fishing regulations apply at Lake Koocanusa?
- Lake Koocanusa carries one special-regulation overlay that overrides Montana's statewide 2026 rules. It reads: "Bull trout CATCH-AND-RELEASE only with a Lake Koocanusa Bull Trout Catch Card in possession (one of only two MT bull-trout angling areas — anglers select EITHER Koocanusa OR Hungry Horse + South Fork Flathead); rainbow trout adipose-clipped fish under 22 in must be released; kokanee salmon 50 / day, 100 in possession; 90-mile Kootenai River reservoir on the MT/BC border behind Libby Dam." Every overlay on this water body is listed in full above.
- Do I need a fishing license to fish Lake Koocanusa?
- Yes. Lake Koocanusa is in Montana, so a valid Montana fishing license is required just as it is anywhere else in the state, issued by Montana Fish, Wildlife & Parks (FWP). The special regulations on this page change the bag, size, slot, or gear rules for Lake Koocanusa; they do not waive the license requirement. Free-fishing days and youth exemptions follow the statewide Montana rules.
- Do Lake Koocanusa's special rules replace Montana's statewide limits?
- Only where they conflict. Montana's statewide 2026 regulations apply on Lake Koocanusa by default; the overlays above replace the matching statewide rule for the species or gear they name, while everything not specifically overridden still follows the statewide rule. When a water-body rule and the statewide rule disagree, the water-body rule wins.