St. Marys HUC8 09040001
A 3,817 km² sub-basin of the Souris-Red-Rainy region in CN, MT. Drought coverage is from the US Drought Monitor (map of 2026-09-01); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
65
Moderate
Drought index
100
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
50%
of 2 reporting
Median flow
87%
p39 of record
Water assets
2,003
1 springs · 1,321 wells
USGS gauges (2)
- Swiftcurrent Creek at Many Glacier MT0501450047 cfsp18 · below normal
- St. Mary River near Babb MT05017500864 cfsp59 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 100 | 0 | 1/2 | p39 |
Top water assets
- 69Boulder Creekriver
- 69Rose Creekriver
- 69Lee Creekriver
- 69Kennedy Creekriver
- 69Swiftcurrent Creekriver
- 69Otatso Creekriver
- 69Wilbur Creekriver
- 69Hudson Bay Creekriver
- 69Hudson Bay Creekriver
- 69Boulder Creekriver