Musselshell River River Levels

Last Updated: February 1, 2026

The Musselshell River is a tributary of the Missouri River that runs through Montana.



15-Day Weather Outlook


Summary

Total streamflow across the Musselshell River was last observed at 148 cfs, and is expected to yield approximately 293 acre-ft of water today; about 100% of normal. Average streamflow for this time of year is 148 cfs, with recent peaks last observed on 2011-06-10 when daily discharge volume was observed at 51,070 cfs.

Maximum discharge along the river is currently at the Musselshell River Near Roundup Mt reporting a streamflow rate of 82.9 cfs. However, the streamgauge with the highest stage along the river is the Musselshell River At Harlowton Mt with a gauge stage of 3.37 ft. This river is monitored from 6 different streamgauging stations along the Musselshell River, the highest being situated at an altitude of 4,668 ft, the Musselshell River Nr Martinsdale.

River Details

Last Updated 2026-01-18
Discharge Volume 293 ACRE-FT
Streamflow 147.6 cfs
+34.6 cfs (+30.62%)
Percent of Normal 100.0%
Maximum 51,070.0 cfs
2011-06-10
Seasonal Avg 148 cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Musselshell River Nr Martinsdale
USGS 06119600
61 cfs 1.81 ft -1.92
Musselshell River At Harlowton Mt
USGS 06120500
65 cfs 3.37 ft 73.46
Musselshell River Ab Mud Cr Nr Shawmut Mt
USGS 06123030
14 cfs 2.52 ft 0
Musselshell River Near Roundup Mt
USGS 06126500
83 cfs 1.75 ft 9.51
Musselshell River At Musselshell Mt
USGS 06127500
72 cfs 2.06 ft -2.17
Musselshell River At Mosby Mt
USGS 06130500
0 cfs 3.36 ft None
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

The Musselshell River is a tributary of the Missouri River, 341.9 miles (550.2 km) long from its origins at the confluence of its North and South Forks near Martinsdale, Montana to its mouth on the Missouri River. It is located east of the Continental divide entirely within Montana in the United States. Counting its pre-confluence tributaries, it measures 425–500 miles (684–805 km) in length.It rises in several forks in the Crazy, Little Belt, and Castle mountains in central Montana. The main branch is formed by the confluence of the North Fork and South Fork in Meagher County, about 25 miles (40 km) east of White Sulphur Springs, Montana, just east of Martinsdale, north of Martinsdale Reservoir, and just west of Meagher County's border with Wheatland County. The North Fork flows south from the Little Belt Mountains through Bair Reservoir, then southeast. The South Fork flows northeast from the Crazy Mountains. From the confluence of these two waterways, the main branch flows roughly due east past Two Dot, Harlowton, and Roundup, then turns north just past Melstone, and continues to the UL Bend on the Missouri River at the beginning of Fort Peck Reservoir.The Musselshell River has also been known as: Cockkleshell River, Mahtush-ahzhah, Muscleshell River, Mustleshell River, Shell River. The Musselshell was entered by the Lewis and Clark Expedition on May 20, 1805 and named by them for the freshwater mussels lining the bank, noting in their journals that the Minnetare people had given the waterway a similar name. The Blackfeet, who hunted buffalo and prepared the meat for winter in the Musselshell area, called it the Dried Meat River.