Upper Missouri-Dearborn HUC8 10030102
A 6,737 km² sub-basin of the Missouri region in 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
78
Healthy
Drought index
56
Abnormally dry
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
17%
of 6 reporting
Median flow
88%
p37 of record
Water assets
2,300
107 springs · 433 wells
USGS gauges (6)
- Missouri River near Great Falls MT060903004,120 cfsp22 · below normal
- Missouri River near Ulm MT060782003,420 cfsp26 · normal
- Missouri River bl Holter Dam nr Wolf Cr MT060665003,550 cfsp34 · normal
- Dearborn River near Craig MT0607350036 cfsp41 · normal
- Missouri River at Cascade MT060740003,550 cfsp47 · normal
- Missouri River at Fort Benton MT060908004,890 cfsp57 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 56 | 0 | 1/6 | p37 |
Top water assets
- 74Kootenai Formation Aquifer — Great Falls Regionaquifer
- 69Dearborn Riverriver
- 69West Fork Falls Creekriver
- 69Whitetail Creekriver
- 69Whitetail Creekriver
- 69Dearborn Riverriver
- 69East Fork Falls Creekriver
- 69Dearborn Riverriver
- 69Dearborn Riverriver
- 69West Fork Falls Creekriver