Rivers in Montana

Saint Mary River at International boundary

Glacier County, MontanaNWS SMBM8USGS 05020500Great Falls office

Below flood stage
3.98ftStage

Observed Tue, Sep 29, 10:10 PM MDT

Flood stage
7.50 ft
Record crest
13.46 ft1975

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood9.50 ft
Moderate flood8.50 ft
Minor flood7.50 ft
Action6.50 ft

Flood outlook

Chance of flooding, October to December

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 23, 2026.

Crest history

54 crests on NOAA’s list since 1908.

#DateStage
1June 21, 197513.46 ft
2June 5, 190812.75 ft
3May 28, 201912.02 ft
4June 7, 199510.99 ft
5March 13, 20039.96 ft
6June 19, 20149.00 ft
7June 13, 19708.75 ft
8May 30, 19678.75 ft
9June 4, 19668.60 ft
10June 20, 19658.59 ft
11June 19, 19748.59 ft
12May 31, 19718.44 ft
13July 1, 20028.30 ft
14June 2, 19978.29 ft
15June 21, 19918.22 ft
16June 12, 19728.06 ft
17June 11, 19897.92 ft
18June 27, 19697.87 ft
19June 9, 20117.80 ft
20June 10, 19967.79 ft
21June 17, 20107.77 ft
22November 9, 20067.75 ft
23May 20, 19937.74 ft
24June 1, 19867.64 ft
25May 26, 20087.58 ft

Most recent crests

  • June 14, 2022: 7.54 ft
  • May 28, 2019: 12.02 ft
  • June 19, 2014: 9.00 ft
  • May 15, 2013: 6.82 ft
  • June 27, 2012: 7.12 ft
  • June 9, 2011: 7.80 ft
  • June 17, 2010: 7.77 ft
  • June 1, 2009: 6.26 ft
  • May 26, 2008: 7.58 ft
  • November 9, 2006: 7.75 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Missouri Basin River Forecast Center. Forecasts are issued as needed during times of high water, but are not routinely available. Stage may be affected by ice during winter months.

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.