Summary
Total streamflow across the
Marias River
was last observed at
305
cfs, and is expected to yield approximately
605
acre-ft of water today; about 35%
of normal.
River levels are low and may signify a drought.
Average streamflow for this time of year is
861 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 Loma Mt
reporting a streamflow rate of 335 cfs.
However, the streamgauge with the highest stage along the river is the
Marias River Near Shelby Mt
with a gauge stage of 3.1 ft.
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 | 2025-11-26 |
| Discharge Volume | 605 ACRE-FT |
| Streamflow |
305.0 cfs
-65.0 cfs (-17.57%) |
| Percent of Normal | 35.44% |
| Maximum |
18,600.0 cfs
2011-06-10 |
| Seasonal Avg | 861 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 |
305 cfs | 3.1 ft | -17.57 | |||||
|
Marias River Near Chester Mt
USGS 06101500 |
249 cfs | 2.94 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.