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 2026-10-13); streamflow classes place each USGS gauge's latest reading against its own day-of-year record.
Health score
62
Moderate
Drought index
0
None
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
100%
of 2 reporting
Median flow
46%
p14 of record
Water assets
2,003
1 springs · 1,321 wells
USGS gauges (2)
- St. Mary River near Babb MT0501750095 cfsp12 · below normal
- Swiftcurrent Creek at Many Glacier MT0501450028 cfsp16 · below normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-19 | 0 | 0 | 2/2 | p14 |
| 2026-10-18 | 0 | 0 | 2/2 | p13 |
| 2026-10-17 | 0 | 0 | 2/2 | p16 |
| 2026-10-16 | 0 | 0 | 2/2 | p18 |
| 2026-10-15 | 0 | 0 | 2/2 | p20 |
| 2026-10-14 | 0 | 0 | 2/2 | p19 |
| 2026-10-13 | 0 | 0 | 1/2 | p24 |
| 2026-10-12 | 0 | 0 | 1/2 | p24 |
| 2026-10-11 | 0 | 0 | 2/2 | p22 |
| 2026-10-10 | 0 | 0 | 1/2 | p24 |
| 2026-10-09 | 0 | 0 | 0/2 | p28 |
| 2026-10-08 | 0 | 0 | 0/2 | p29 |
| 2026-10-07 | 0 | 0 | 0/2 | p32 |
| 2026-10-06 | 0 | 0 | 0/2 | p32 |
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