Flathead River River Levels

Last Updated: December 4, 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 20,330 cfs, and is expected to yield approximately 40,324 acre-ft of water today; about 86% of normal. Average streamflow for this time of year is 23,747 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 Perma Mt reporting a streamflow rate of 8,540 cfs. This is also the highest stage along the Flathead River, with a gauge stage of 8.93 ft at this location. 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 2025-12-04
Discharge Volume 40,324 ACRE-FT
Streamflow 20,330.0 cfs
-493.0 cfs (-2.37%)
Percent of Normal 85.61%
Maximum 165,650.0 cfs
2012-06-27
Seasonal Avg 23,747 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
463 cfs 4.73 ft -4.34
Flathead River At Columbia Falls Mt
USGS 12363000
3580 cfs 3.76 ft -2.19
Flathead River Near Polson Mt
USGS 12372000
8210 cfs 5.88 ft 0
Flathead River At Perma Mt
USGS 12388700
8540 cfs 8.93 ft 0.59
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.