USGS Streamgage 12377150
Mission Creek ab reservoir near St. Ignatius, MT
Mission Creek ab reservoir near St. Ignatius, MT is USGS streamgage 12377150 in Montana, monitoring river discharge in hydrologic subbasin 17010212. It drains a watershed of about 14 square miles. Discharge records at this site go back to 1982. Typical flow runs near 110.9 cfs in July and 20.1 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 14 sq mi
- Gauge elevation
- 3,415 ft
- Subbasin (HUC-8)
- 17010212
- Coordinates
- 47.32019, -113.98789
- USGS site number
- 12377150
- Records begin
- 1982-10-01 (44 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 43 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 | 8.2 | 10.7 | 14.5 | |
| February | 7.2 | 9.4 | 13.2 | |
| March | 7.9 | 10.2 | 14.7 | |
| April | 10.4 | 20.1 | 44.8 | |
| May | 43.8 | 86.3 | 202.6 | |
| June | 104.4 | 173 | 306 | |
| July | 62.1 | 110.9 | 194.3 | |
| August | 29.5 | 45.7 | 74.9 | |
| September | 18 | 26.5 | 46.8 | |
| October | 14.6 | 22.5 | 37 | |
| November | 13 | 19.5 | 30.4 | |
| December | 10.1 | 13.4 | 18.8 |
All values in cubic feet per second (cfs).