Rivers in Idaho
Lemhi River near Lemhi
Below flood stage
3.53ftStage
Observed Tue, Sep 22, 3:00 PM MDT
- Flood stage
- 6.50 ft
- Forecast crest
- 3.51 ftTue, Sep 22, 6:00 PM MDT
- Record crest
- 7.19 ft1984
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 10.00 ft |
| Moderate flood | 8.50 ft |
| Minor flood | 6.50 ft |
| Action | 6.00 ft |
- 10.00 ftMainy bridges along Highway 28 will be overtopped and flooded from Lemhi to Tendoy.
- 8.50 ftPossible damage to irrigation diversion headgates and ditches.
- 7.00 ftExpect possible flooding to Highway 28 from Tendoy to Salmon.
- 6.50 ftExpect flooding to ranchland adjacent to the river from Tendoy to Salmon.
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 September 22, 2026.
Crest history
16 crests on NOAA’s list since 1971.
| # | Date | Stage |
|---|---|---|
| 1 | June 21, 1984 | 7.19 ft |
| 2 | January 29, 2026 | 7.07 ft |
| 3 | July 6, 1975 | 6.72 ft |
| 4 | June 5, 2017 | 6.70 ft |
| 5 | June 24, 2011 | 6.67 ft |
| 6 | June 24, 1982 | 6.62 ft |
| 7 | June 2, 1986 | 6.22 ft |
| 8 | June 22, 2009 | 6.13 ft |
| 9 | June 13, 2022 | 6.12 ft |
| 10 | June 5, 1995 | 6.06 ft |
| 11 | June 27, 1971 | 6.01 ft |
| 12 | June 17, 1999 | 5.83 ft |
| 13 | June 1, 2018 | 5.81 ft |
| 14 | June 10, 1996 | 5.76 ft |
| 15 | June 17, 2010 | 5.63 ft |
| 16 | June 2, 2025 | 4.76 ft |
Most recent crests
- January 29, 2026: 7.07 ft
- June 2, 2025: 4.76 ft
- June 13, 2022: 6.12 ft
- June 1, 2018: 5.81 ft
- June 5, 2017: 6.70 ft
- June 24, 2011: 6.67 ft
- June 17, 2010: 5.63 ft
- June 22, 2009: 6.13 ft
- June 17, 1999: 5.83 ft
- June 10, 1996: 5.76 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.