Marias HUC8 10030203
A 9,553 km² sub-basin of the Missouri 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
72
Moderate
Drought index
167
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
0%
of 3 reporting
Median flow
106%
p52 of record
Water assets
1,040
4 springs · 176 wells
USGS gauges (3)
- Marias River near Chester MT06101500509 cfsp38 · normal
- Marias River near Loma MT06102050615 cfsp52 · normal
- Marias River near Shelby MT06099500460 cfsp78 · above normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 167 | 0 | 0/3 | p52 |
Top water assets
- 68Sullivan Damreservoir
- 67Dry Fork Marias Riverriver
- 67Marias Riverriver
- 67Marias River Near Loma Mtriver
- 67Dry Fork Marias Riverriver
- 67Marias River Near Chester Mtriver
- 67Strudy Damreservoir
- 67Echo Reservoirreservoir
- 67Dry Fork Marias Riverriver
- 67Marias Riverriver