USGS Streamgage 05018500
St. Mary Canal at St. Mary Crossing near Babb, MT
St. Mary Canal at St. Mary Crossing near Babb, MT is USGS streamgage 05018500 in Montana, monitoring river discharge in hydrologic subbasin 10010002. Discharge records at this site go back to 1918. Typical flow runs near 591.5 cfs in July and 64.2 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Montana
- Gauge elevation
- 4,455 ft
- Subbasin (HUC-8)
- 10010002
- Coordinates
- 48.94697, -113.37533
- USGS site number
- 05018500
- Records begin
- 1918-07-01 (108 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 108 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
Only 10 of 12 months have enough record to summarize; the rest are omitted.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| February | — | 0 | — | |
| March | 0 | 0 | 215.7 | |
| April | 0 | 64.2 | 550.6 | |
| May | 0 | 494.8 | 658.1 | |
| June | 16.5 | 588.4 | 693 | |
| July | 260.2 | 591.5 | 693.5 | |
| August | 214.2 | 577.2 | 687.5 | |
| September | 0 | 239 | 623.1 | |
| October | 0 | 0 | 107.2 | |
| November | 0 | 0 | 37.6 |
All values in cubic feet per second (cfs).