Prospect Creek at Thompson Falls, MT
River level and flood forecast · Sanders County
Normal0.4 ftas of Mon 1:15 PM
The river is 7.1 ft below flood stage (7.5 ft).
Forecast to hold near 0.4 ft through Mon, Oct 19, 12 PM.
Flow: 37 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 9:36 AM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 9 ft |
| Moderate flood stage | 8 ft |
| Flood stage | 7.5 ft |
| Action stage | 6.5 ft |
| Record crest (January 16, 1974) | 9.86 ft |
What floods at each level
From the National Weather Service, highest first.
- 8.5 ftA petroleum gas pipeline becomes exposed underneath the creek due to high flood flows.
- 8.19 ftHomes along Prospect Creek become surrounded with water from Prospect Creek.
- 8.1 ftWater begins flowing across Prospect Creek Road.
- 7.5 ftRoad washouts are possible along Prospect Creek Road.
Highest crests on record
- 9.86 ft — January 16, 1974
- 9.54 ft — February 9, 1996
- 8.1 ft — March 19, 2017
- 7.6 ft — May 13, 1971
- 7.6 ft — May 21, 1956
Recent crests: 6.35 ft (December 11, 2025) · 3.55 ft (March 28, 2025) · 5.01 ft (May 7, 2022) · 3.99 ft (May 2, 2021) · 4.54 ft (May 31, 2020)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (PRCM8); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.