Can you keep a largemouth bass in Montana?

Closes each year From the third Saturday in May through June 30, the bag drops to 1 fish a day, which must be over 22 inches — a spawning-protection window before the regular 5-fish rule resumes

Flathead Lake has no largemouth-specific override, so the Western District rule applies there in full, including the spring trophy-only window.

FWP source page

Central District keeps a single combined bass limit rather than splitting largemouth and smallmouth as the Western District does.

FWP source page

What we left out on purpose

• Bighorn Lake (a separate water from the Bighorn River this site tracks) carries its own sauger/walleye numbers (6 combined daily, only 3 may be sauger) — not modelled here since this site follows the river, not the lake.
• Gallatin River carries a boat-fishing closure between the Yellowstone National Park boundary and the East Gallatin River, and a fixed general season (third Saturday in May – November 30) on the stretch from Porcupine Creek Road to the West Fork — gear/access rules rather than size or bag numbers, not modelled in this schema.
• The Madison River's Lyons-Bridge-to-Ennis-Bridge stretch is actually two adjoining catch-and-release segments (Lyons–Varney and Varney–Ennis) with a near-identical but not byte-for-byte identical rule (one restricts all trout, the other only rainbow). This site's tracked coordinate sits almost exactly at Varney Bridge, the boundary between them — both are described together rather than forcing a guess about which side of the bridge the coordinate falls on.
• Channel catfish, shovelnose sturgeon, tiger muskie and walleye/sauger are not modelled for these six waters because none of the six carries its own number for them and none is a species this site's water reports actually target.
• Montana's hundreds of further named-water exceptions beyond the six waters this site tracks are not modelled — the same restraint used for Colorado's, Kansas's, Michigan's and Minnesota's named-water exceptions.