Summary
Total streamflow across the
Marias River
was last observed at
5,490
cfs, and is expected to yield approximately
10,889
acre-ft of water today; about 226%
of normal.
River levels are high.
Average streamflow for this time of year is
2,432 cfs,
with recent peaks last observed
on
2011-06-10 when daily discharge volume was observed at
18,600 cfs.
Maximum discharge along the river is currently at the
Marias River Near Shelby Mt
reporting a streamflow rate of 5,490 cfs.
This is also the highest stage along the Marias River, with a gauge stage of
7.55 ft at this location.
This river is monitored from 3 different streamgauging stations along the Marias River, the highest being situated at an altitude of 3,099 ft, the
Marias River Near Shelby Mt.
River Details
| Last Updated | 2025-12-23 |
| Discharge Volume | 10,889 ACRE-FT |
| Streamflow |
5,490.0 cfs
+3940.0 cfs (+254.19%) |
| Percent of Normal | 225.71% |
| Maximum |
18,600.0 cfs
2011-06-10 |
| Seasonal Avg | 2,432 cfs |
River Streamflow Levels
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Marias River Near Shelby Mt
USGS 06099500 |
5490 cfs | 7.55 ft | 254.19 | |||||
|
Marias River Near Chester Mt
USGS 06101500 |
253 cfs | 2.95 ft | 0 | |||||
|
Marias River Near Loma Mt
USGS 06102050 |
335 cfs | 0.86 ft | -3.18 |
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile
The Marias River is a tributary of the Missouri River, approximately 210 mi (338 km) long, in the U.S. state of Montana. It is formed in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River. It flows east, through Lake Elwell, formed by the Tiber Dam, then southeast, receiving the Teton River at Loma, 2 mi. (3.2 km) above its confluence with the Missouri.
The river was explored in 1805 by the Lewis and Clark Expedition. Some of the men on the expedition mistook it for the main branch of the Missouri until their subsequent discovery of the Great Falls of the Missouri near Great Falls, Montana. The river was named by Meriwether Lewis after his cousin, Maria Wood. Lewis led a small detachment of men to further explore the Marias River on the Expedition's return trip in 1806 to determine if the river ventured north above the Canada border, and he killed a young Blackfeet warrior trying to steal horses and a gun from the small detachment.
The river was the scene of the 1870 Marias Massacre.The Marias is a Class I river from Tiber Dam to its confluence with the Missouri River for public access for recreational purposes.The Montana Watershed Coordination Council is an advocate for the river.The Marias River Bridge was listed on the National Register of Historic Places in 2012.