Varies by water — most rivers: 12-inch minimum on rainbows
Slot: Many blue-ribbon rivers are catch-and-release only...
Daily Bag Limit
5 trout per day (many rivers are catch-and-release for rainbows)
Possession: 10
Season
Year-round on most rivers. Some streams closed in winter.
Slot Limit
⚠ Slot limit in effect: Many blue-ribbon rivers are catch-and-release only for rainbow and brown trout
Special Rules & Notes
Montana's famous rivers (Madison, Gallatin, Yellowstone, Big Hole) are largely catch-and-release for wild trout. Some sections allow harvest of hatchery fish (marked with clipped adipose fin).
Popular Montana Waters
Madison River
Yellowstone River
Gallatin River
Big Hole River
Missouri River (Craig section)
Tips for Montana Rainbow Trout Fishing
Montana is a bucket-list destination for trout anglers. The Madison and Yellowstone rivers are legendary.
Much of Montana's best trout fishing is catch-and-release — bring good forceps and a rubber landing net.
Common Questions
Many of Montana's famous rivers are catch-and-release for wild rainbow and brown trout. Some sections allow harvest of hatchery fish identified by a clipped adipose fin. Always check the specific regulation for the stretch of river you're fishing.
The Madison River is often cited as one of the best trout rivers in the world. The Missouri River below Holter Dam near Craig is also renowned for its density of large rainbow trout.
Important: Fishing regulations change annually. This page reflects regulations for 2026 but always verify current rules with Montana Fish, Wildlife & Parks (FWP) before fishing. Some waters have special regulations that differ from the statewide rules.