Can you keep a combined trout (brown, rainbow, golden, cutthroat and grayling) in Montana?

Bull trout may not be targeted anywhere in the Western District and must be released immediately if caught.

FWP source page

Closes each year Extended season (December 1 – third Saturday in May) is catch-and-release only for all trout, artificial lures/maggots/aquatic insects only. The 3-fish general-season rule below applies from the third Saturday in May through November 30

Well below the Western District's standard 5-fish rule, and cutthroat may not be kept at all on this stretch — the segment matching this site's tracked location on the Bitterroot.

FWP source page

Neither the Bighorn nor the Gallatin carries its own trout override — both run on the plain Central District standard, a genuine finding in itself given the Bighorn's reputation as a trophy tailwater.

FWP source page

Same Central District standard bag as the Bighorn and Gallatin, but with a local override: cutthroat trout may not be kept at all on this stretch.

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.