The cutthroat trout, Montana’s state fish, lives in cold, clear mountain water. Although native to the state, it’s been outcompeted by invasive brown and brook trout, and interbred with rainbows, and its population is severely diminished from its historic range. Yellowstone cutthroat are native to the Yellowstone River watershed. The westslope cutthroat, a subspecies of the Yellowstone cutt, is native west of the Continental Divide and in some watersheds on the east side. 10 – 18.”
Although this bottomfeeder is not considered a desirable gamefish, they generally inhabit the same cold streams and rivers as trout in southern and western Montana do. They spawn in the fall, scattering their eggs in gravel beds. 10-18.”
Rare in the lower 48, but found in the upper Big Hole River and in parts of northwestern Montana. It was originally a stream fish, but now lives mainly in mountain lakes where it was stocked, according to gofishn.com. 10-18.”
The pallid sturgeon is the larger of the two species of sturgeon east of the Continental Divide in Montana. It can grow to 60 pounds. Because biologists know so little about this rare species, it’s a Montana Fish of Special Concern, is on the Federal Endangered Species List and is the subject of ongoing FWP research. Pallid sturgeon inhabit the lower Yellowstone River during spring and summer, and during fall and winter migrate to the Missouri River below the confluence with the Yellowstone.
Flathead Lake Monster
With relatives in Vermont, Scotland, New Brunswick and Patagonia, this prehistoric aquatic creature is native to Montana, and roams all parts of Flathead Lake. It was first seen in 1889 from the lake steamer U.S. Grant, skippered by Capt. James C. Kerr. Sightings of the large creature have been documented in every decade since.
These fish evolved in Europe and western Asia, and were introduced to Montana in 1889 in the Madison River. Browns live in most of Montana, generally in lower gradient, larger streams than cutthroat and rainbow, and also in reservoirs. They are “great competitors and generally are more tolerant of dewatering and other environmental disturbances than other trout species,” according to the Montana FWP. Brown trout spawn in gravel redds in the fall, which gives them an advantage since their spawning and incubation period is outside irrigation season. 12-20 inches is typical size, and the state record is 29 pounds.
The rainbow trout is Montana’s number one game fish – the state record is 33 pounds, and fish up to 10 pounds are common in some fisheries. Only the rainbow trout of the upper Kootenai River are native, and the rest were introduced in the late 19th century. The state has stocked hundreds of millions of rainbow in the last 100 years, according to the FWP Field Guide. Rainbow trout inhabit ponds, reservoirs, lakes and streams, and eat plankton, aquatic and terrestrial insects, and occasionally smaller fishes. They spawn in early spring in running water.