Flathead River River Levels

Last Updated: December 15, 2025

The Flathead River is a 158-mile-long river located in western Montana, USA.


Summary

Total streamflow across the Flathead River was last observed at 42,090 cfs, and is expected to yield approximately 83,485 acre-ft of water today; about 159% of normal. River levels are high. Average streamflow for this time of year is 26,422 cfs, with recent peaks last observed on 2012-06-27 when daily discharge volume was observed at 165,650 cfs.

Maximum discharge along the river is currently at the Flathead River At Columbia Falls Mt reporting a streamflow rate of 14,600 cfs. However, the streamgauge with the highest stage along the river is the Flathead River At Perma Mt with a gauge stage of 10.53 ft. This river is monitored from 4 different streamgauging stations along the Flathead River, the highest being situated at an altitude of 3,983 ft, the Flathead River At Flathead British Columbia.

River Details

Last Updated 2025-12-15
Discharge Volume 83,485 ACRE-FT
Streamflow 42,090.0 cfs
-370.0 cfs (-0.87%)
Percent of Normal 159.3%
Maximum 165,650.0 cfs
2012-06-27
Seasonal Avg 26,422 cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Flathead River At Flathead British Columbia
USGS 12355000
1190 cfs 5.88 ft -18.49
Flathead River At Columbia Falls Mt
USGS 12363000
14600 cfs 7.51 ft -17.51
Flathead River Near Polson Mt
USGS 12372000
13500 cfs 7.8 ft 8.87
Flathead River At Perma Mt
USGS 12388700
12800 cfs 10.53 ft 17.43
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

The Flathead River (Salish: ntx̣ʷetkʷ, ntx̣ʷe ), in the northwestern part of the U.S. state of Montana, originates in the Canadian Rockies to the north of Glacier National Park and flows southwest into Flathead Lake, then after a journey of 158 miles (254 km), empties into the Clark Fork. The river is part of the Columbia River drainage basin, as the Clark Fork is a tributary of the Pend Oreille River, a Columbia River tributary. With a drainage basin extending over 8,795 square miles (22,780 km2) and an average discharge of 11,380 cubic feet per second (322 m3/s), the Flathead is the largest tributary of the Clark Fork and constitutes over half of its flow.