USGS Streamgage 12323700
Mill Creek at Opportunity, MT
Mill Creek at Opportunity, MT is USGS streamgage 12323700 in Montana, monitoring river discharge in hydrologic subbasin 17010201. It drains a watershed of about 42 square miles. Discharge records at this site go back to 2003. Typical flow runs near 22.6 cfs in July and 13.6 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Drainage area
- 42 sq mi
- Gauge elevation
- 4,965 ft
- Subbasin (HUC-8)
- 17010201
- Coordinates
- 46.1136, -112.82806
- USGS site number
- 12323700
- Records begin
- 2003-04-01 (23 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 23 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 | 0.6 | 5.1 | 9.3 | |
| February | 0.6 | 5.4 | 9.9 | |
| March | 0.9 | 7.1 | 17.3 | |
| April | 1.5 | 13.6 | 34.4 | |
| May | 9.1 | 49.1 | 118 | |
| June | 25.1 | 71.4 | 155.3 | |
| July | 3.1 | 22.6 | 59.5 | |
| August | 1.2 | 3.6 | 13.7 | |
| September | 0.6 | 2 | 9.8 | |
| October | 0.7 | 4.7 | 12.1 | |
| November | 1.2 | 5.7 | 12.7 | |
| December | 0.9 | 4.4 | 9.2 |
All values in cubic feet per second (cfs).