Skip to main content

Cutthroat Trout

Cutthroat Trout

Montana is home to two native cutthroat trout subspecies that together form the state fish, the Blackspotted Cutthroat Trout.

The Westslope Cutthroat Trout historically ranged throughout Montana west of the Continental Divide and the upper Missouri River drainage, while the Rocky Mountain Cutthroat Trout (formerly called Yellowstone Cutthroat) is native to the Yellowstone River drainage of southwest and south-central Montana.

Also known as Blackspotted Cutthroat Trout, Westslope Cutthroat Trout, Rocky Mountain Cutthroat Trout, formerly called Yellowstone Cutthroat

Physical Characteristics:
  • Both species are distinguished by prominent red slashes on their lower jaws.
  • Westslope cutthroats tend to be smaller (6-16 inches average, rarely exceeding 18 inches) with more small spots concentrated toward the tail and silvery-greenish coloration.
  • Rocky Mountain cutthroats are generally larger with golden coloration and bigger, more widely distributed spots.
  • They're more predatory, growing up to 15 pounds in mountain lakes.

What to know

Habitat Distribution

  • Westslope Cutthroat Trout historically ranged throughout Montana west of the Continental Divide and the upper Missouri River drainage, while the Rocky Mountain Cutthroat Trout is native to the Yellowstone River drainage of southwest and south-central Montana.
  • Pure populations are now limited to headwater streams, with westslope cutthroats occupying only 33,500 miles (59%) of their historic 56,500-mile range.

Key Locations

  • Key Montana waters include Swan Valley streams, Yellowstone River drainage, upper Missouri River system, Clark Fork watershed, Flathead River system, and mountain lakes in the Absaroka-Beartooth Wilderness.
  • The Missouri River near Great Falls, Madison River, and various spring creeks offer excellent opportunities.

Specific Spots

  • Target slack water areas like pools, undercut banks, and areas with cover.
  • Look for deeper, slower pools in winter and concentrate on structure like bubble lines, boulder gardens, and drop-offs.

Cutthroat Trout FAQ

Answers from onWater's species guide.

What flies work for Cutthroat Trout in Montana?

Top dry flies include Royal Wulff (size 10), Elk Hair Caddis (size 16), Chubby Chernobyl for terrestrial fishing, and attractor patterns like Parachute Adams. Essential nymphs are Pheasant Tail (size 18), Prince Nymph (size 14), and Czech nymphs.

When is the best time to fish for Cutthroat Trout in Montana?

Montana's general fishing season for most rivers opens the third Saturday in May. Late spring through early fall, from late May through October, with peak fishing occurring June through September. Summer provides the most consistent dry fly fishing.

How do you catch Cutthroat Trout in Montana?

Focus presentations on natural drifts, proper mending, and matching local insect hatches. Target slack water areas like pools, undercut banks, and areas with cover. Look for deeper, slower pools in winter and concentrate on structure like bubble lines, boulder gardens, and drop-offs.

What do Cutthroat Trout eat?

Both subspecies primarily feed on aquatic insects, zooplankton, and terrestrial insects that fall into the water. Larger fish over 12 inches may eat sculpins and other small vertebrates. Rocky Mountain cutthroats eat fish as part of their diet.

Where do Cutthroat Trout live in Montana?

Westslope Cutthroat Trout historically ranged throughout Montana west of the Continental Divide and the upper Missouri River drainage, while the Rocky Mountain Cutthroat Trout is native to the Yellowstone River drainage of southwest and south-central Montana.

Fish smarter with real-time insights

Whether you're en route and conditions shift or you're looking for the best spot based on current flows, we enable you to make informed decisions on the fly.

See it in the app

Most maps show you water.
onWater shows you Cutthroat Trout.

  1. 01 · Species map filter

    Map every Cutthroat Trout water

    Pick Cutthroat Trout and the map zeroes in on the waters they call home. No more guessing which lake holds them.

  2. 02 · Waterbody species

    Tap any water. See what lives there.

    Species, behavior and seasonal patterns for every lake, river and pond, before you leave the driveway.

  3. 03 · Angler Intelligence

    Ask how to catch Cutthroat Trout

    Tactics, gear and timing from onWater's AI fishing guide, tuned to the species and the water you're on.

Stop guessing where Cutthroat Trout are.

Open the map, filter by Cutthroat Trout, and head to water that holds them. Download onWater and plan your next trip in minutes.

  • Species map filter
  • Angler Intelligence
  • Fishing journal
Try onWater+ for free

Explore other species

Trout, bass, salmon, panfish and everything in between. Each guide unpacks the behavior, seasons, and tactics that put fish in the net.

No species information available.

Montana licenses and regulations

Explore nearby waters

Explore Montana waters

Top fishing waters

Popular Cities

Loading popular cities...

Smarter Fishing Starts in the App.

onWater Fish gives you everything you need to plan smarter, fish better, and own every trip from first cast to last.