The Musselshell River is a tributary of the Missouri River, approximately 292 mi (470 km) long, in central Montana in the United States. It rises in several forks in the Crazy, Little Belt, and Castle moutains in central Montana. The main branch is formed by the confluence of the North Fork and South Fork in western Wheatland County. It flows east past Harlowton, northeast past Roundup, and then north, where it joins the Missouri as one of the arms of Fort Peck Lake.
The MusselshellRiver begins at the confluence of the North and South Forks Musselshell, in a broad valley that lies north of the Crazy Mountains and to the east of White Sulphur Springs, MT.
The river ends on the south shores of Fort Peck Lake, near the southern tip of the UL Bend Wilderness, 360 miles later.
Overall, don't plan a visit to Montana with the MusselshellRiver as the primary destination for fishing, except for perhaps the excellent smallmouth bass fishing it provides near Fort Peck Lake.