Upper Yellowstone-Pompeys Pillar HUC8 10070007
A 5,202 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
54
Moderate
Drought index
228
Severe
Area in D2+
27.82%
0% exceptional (D4)
Gauges below normal
—
no gauges reporting
Median flow
—
of normal for the date
Water assets
1,010
32 springs · 297 wells
USGS gauges (0)
No active discharge gauges in this sub-basin.
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 228 | 27.82 | — | — |
Top water assets
- 67Yellowstone Riverriver
- 67Fly Creekriver
- 67Yellowstone Riverriver
- 67Railroad Creekriver
- 67Yellowstone Riverriver
- 67Arrow Creekriver
- 67Fly Creekriver
- 67Railroad Creekriver
- 67Buffalo Creekriver
- 67Fly Creekriver