Montana splits into three fishing districts and only one of them has an opening day. If you are fishing rivers west of the Continental Divide, the third Saturday in May is the date that matters; everywhere else in the state, the water is open.
Every season we have verified in Montana
One block per rule, because a single species can be on two calendars in the same state depending on the water. The band under each heading is the legal season; the row under it is what our own data says the fish are doing.
Trout — Western District rivers and streams
The regulation reads "Open third Saturday in May through November 30, unless otherwise specified in Exceptions to Standard Regulations". The Western District is every water in Montana west of the Continental Divide, which is most of the famous trout water in the state bar the Missouri and the Yellowstone. The date moves: May 16 in 2026, May 17 in 2025.
Trout — Central and Eastern District rivers and streams
Both districts read "Open all year" for rivers and streams, with the Central District adding "unless otherwise specified in Exceptions to Standard Regulations". So the Madison, the Bighorn and the lower Missouri are fishable in February while the Bitterroot is not.
Trout — Lakes and reservoirs, all three districts
Every lake and reservoir in Montana reads "Open all year" under the standard regulations. The state tells anglers to work in this order: identify the district, read its standard regulations, then look up the specific water in the Exceptions — and if it is listed there, the exception replaces the standard rule entirely.
Read on 2026-09-14 from Montana Fish, Wildlife and Parks. Legal dates were read on the agency’s own page on the date shown beside each entry. Seasons change: the agency link is always the last word.
What the water is doing while the season is open
This is the part an agency page will not tell you. The temperature row above is the seasonal curve we use for the 15 of 26 Montana waters we track on a trout river profile, and it is why an opening date and a fishable date are not the same thing. A season that opens while the water is still in the forties is a legal invitation, not a biological one: the fish are there, they are just not eating on your schedule yet. Cross the legal band against the activity row before you book the day off.
Where to fish it
We publish a daily report for 26 Montana waters, each with live flow or tide and today's conditions.
- Madison River — Madison County
- Bighorn River — Yellowstone County
- Gallatin River — Gallatin County
- Fort Peck Lake — Valley County
- Flathead Lake — Lake County
- Rock Creek — Lake County
- Bitterroot River — Missoula County
- Georgetown Lake — Granite County
- Canyon Ferry Lake — Broadwater County
- Clark Fork River (Missoula) — County
The licence is a separate question
An open season is not permission to fish. Montana requires a licence from age 12, and residents pay from $31.00 against $117.50 for visitors. What a Montana licence costs and where to buy it →
Questions
When does fishing season open in Montana?
It depends on the species: trout may 16 to november 30; trout open all year; trout open all year. Every date on this page was read off Montana FWP on 2026-09-14.
Do I need a licence to fish in Montana?
Yes. Montana requires a fishing licence from age 12, from $31.00 for residents. A season being open is not permission to fish: the licence is separate and so are the size and bag limits.
Are these Montana dates going to change?
Some of them, and the page says which. Dates written as a rule in the regulations are calculated here for 2026, so they follow the rule rather than going stale. Dates the agency sets each year are shown as exactly that, with no calendar band, because inventing one would be worse than leaving it empty.