Rivers in Montana

Prospect Creek at Thompson Falls

Sanders County, MontanaNWS PRCM8USGS 12390700Missoula office

Below flood stage
0.50ftStage

Observed Sat, Sep 26, 2:15 AM MDT

Flood stage
7.50 ft
Forecast crest
0.53 ftSun, Sep 27, 6:00 AM MDT
Record crest
9.86 ft1974

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood9.00 ft
Moderate flood8.00 ft
Minor flood7.50 ft
Action6.50 ft
  1. 8.50 ftA petroleum gas pipeline becomes exposed underneath the creek due to high flood flows.
  2. 8.19 ftHomes along Prospect Creek become surrounded with water from Prospect Creek.
  3. 8.10 ftWater begins flowing across Prospect Creek Road.
  4. 7.50 ftRoad washouts are possible along Prospect Creek Road.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor floodingUnder 5%
Moderate floodingUnder 5%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 25, 2026.

Crest history

16 crests on NOAA’s list since 1956.

#DateStage
1January 16, 19749.86 ft
2February 9, 19969.54 ft
3March 19, 20178.10 ft
4May 13, 19717.60 ft
5May 21, 19567.60 ft
6May 19, 20087.27 ft
7May 11, 19767.09 ft
8June 1, 19727.09 ft
9May 17, 19976.94 ft
10April 25, 20126.52 ft
11December 11, 20256.35 ft
12April 14, 20026.23 ft
13May 7, 20225.01 ft
14May 31, 20204.54 ft
15May 2, 20213.99 ft
16March 28, 20253.55 ft

Most recent crests

  • December 11, 2025: 6.35 ft
  • March 28, 2025: 3.55 ft
  • May 7, 2022: 5.01 ft
  • May 2, 2021: 3.99 ft
  • May 31, 2020: 4.54 ft
  • March 19, 2017: 8.10 ft
  • April 25, 2012: 6.52 ft
  • May 19, 2008: 7.27 ft
  • April 14, 2002: 6.23 ft
  • May 17, 1997: 6.94 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Northwest River Forecast Center. Forecasts are issued routinely year-round.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.