Rivers in Montana
Sun River near Simms
Below flood stage
2.93ftStage
Observed Sun, Sep 20, 2:30 PM MDT
- Flood stage
- 7.50 ft
- Record crest
- 13.70 ft1964
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 10.50 ft |
| Moderate flood | 8.50 ft |
| Minor flood | 7.50 ft |
| Action | 6.00 ft |
- 12.00 ftMajor flooding. More than 100,000 acres flood.
- 10.80 ftAt 10.8 Feet - June 20 2018 - Flooding in the city of Sun River similar to 2011. Most streets under water. Photos estimate water 2 to 4 feet deep. Highway 200 Closed from the 89 Junction all the way to the 287 Junction. Roger's Pass had a culvert washout which closed that section.
- 10.70 ftJune 2018 - 1st and 2nd street flood in Sun River. Gravel washed away roadway, exposing optic cables. In Fort Shaw - North Fort Shaw Road completely destroyed. Culverts under roadway were exposed.
- 9.10 ftMay 27, 2019 - At 9.1 feet - Streets and homes in Sun River flooded. Not as bad as the 2018 flood. Highway 200 had water over the highway, with flaggers. Water around homes. Fields did flood.
- 9.00 ftMuch of the valley is flooded. Highway 200 flooded. Many homes as well as agricultural land floods.
- 8.50 ftHwy 200 through town of Sun River, between 1st St and 3rd St, under water. Significant inundation of town between river to W, N, and E of town to beyond W Carroll St/Steell St. Sun River-Cascade Rd inundated for approx 1/3 mile to south of town.
- 8.00 ftWater starting to cover Hwy 200 between 1st St and 2nd ST. River well out of banks W, N and E of town and filling old oxbows near town and Hwy 200.
- 7.50 ftRiver out of banks and across highway at Sun River (town). Water over Fairfield Road. River within banks at Simms and Fort Shaw. About two dozen homes in Sun River (town) become isolated.
- 7.00 ftMinor overflow between Fort Shaw and Sun River (town) where the river meanders and gets into the old river bed.
- 6.50 ftSome overflow between Fort Shaw and Sun Siver (town) where the river meanders and gets into the old river bed.
- 6.00 ftRiver is bankfull.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | Under 5% |
| Moderate flooding | Under 5% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 26, 2026.
Crest history
41 crests on NOAA’s list since 1953.
| # | Date | Stage |
|---|---|---|
| 1 | June 9, 1964 | 13.70 ft |
| 2 | June 20, 1975 | 12.48 ft |
| 3 | June 20, 2018 | 10.75 ft |
| 4 | June 8, 2011 | 9.87 ft |
| 5 | May 27, 2019 | 9.15 ft |
| 6 | June 4, 1953 | 8.30 ft |
| 7 | May 12, 2018 | 8.10 ft |
| 8 | May 26, 2008 | 8.08 ft |
| 9 | June 2, 1972 | 8.04 ft |
| 10 | May 22, 1981 | 7.90 ft |
| 11 | May 15, 1976 | 7.88 ft |
| 12 | June 7, 2012 | 7.87 ft |
| 13 | June 1, 1967 | 7.79 ft |
| 14 | June 13, 1997 | 7.36 ft |
| 15 | May 29, 1971 | 7.15 ft |
| 16 | June 17, 1974 | 7.14 ft |
| 17 | June 7, 1978 | 6.77 ft |
| 18 | July 1, 1969 | 6.68 ft |
| 19 | June 6, 1970 | 6.51 ft |
| 20 | June 24, 2002 | 6.46 ft |
| 21 | June 1, 2009 | 6.21 ft |
| 22 | May 27, 1979 | 6.06 ft |
| 23 | June 5, 1999 | 6.00 ft |
| 24 | June 12, 2006 | 5.97 ft |
| 25 | May 27, 2003 | 5.88 ft |
Most recent crests
- May 27, 2019: 9.15 ft
- June 20, 2018: 10.75 ft
- May 12, 2018: 8.10 ft
- June 25, 2014: 5.00 ft
- June 9, 2013: 4.98 ft
- June 7, 2012: 7.87 ft
- June 8, 2011: 9.87 ft
- June 6, 2010: 4.33 ft
- June 1, 2009: 6.21 ft
- May 26, 2008: 8.08 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.