USGS Streamgage 12335100
Blackfoot River ab Nevada Creek near Helmville, MT
Blackfoot River ab Nevada Creek near Helmville, MT is USGS streamgage 12335100 in Montana, monitoring river discharge in hydrologic subbasin 17010203. It drains a watershed of about 498 square miles. Discharge records at this site go back to 1999. Typical flow runs near 342.1 cfs in July and 277.9 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 498 sq mi
- Gauge elevation
- 4,264 ft
- Subbasin (HUC-8)
- 17010203
- Coordinates
- 46.91879, -113.01499
- USGS site number
- 12335100
- Records begin
- 1999-10-01 (27 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 26 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | 108.7 | 134 | 164.6 | |
| February | 95.1 | 128.9 | 159.8 | |
| March | 112.5 | 145 | 271.4 | |
| April | 136.8 | 277.9 | 634 | |
| May | 388.6 | 873.8 | 1,776.5 | |
| June | 514.6 | 892.1 | 1,571 | |
| July | 231.4 | 342.1 | 613.5 | |
| August | 143.8 | 186.5 | 267 | |
| September | 133.1 | 163.9 | 205 | |
| October | 138.5 | 166.3 | 198.8 | |
| November | 134.5 | 159.6 | 201 | |
| December | 118.7 | 144.6 | 174.3 |
All values in cubic feet per second (cfs).