Lower Yellowstone-Sunday HUC8 10100001
A 12,447 km² sub-basin of the Missouri region in 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
57
Moderate
Drought index
98
Abnormally dry
Area in D2+
4.34%
0% exceptional (D4)
Gauges below normal
100%
of 2 reporting
Median flow
72%
p16 of record
Water assets
3,027
213 springs · 687 wells
USGS gauges (2)
- Yellowstone River at Forsyth MT062950005,010 cfsp15 · below normal
- Yellowstone River at Miles City, MT063090005,680 cfsp18 · below normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-10-20 | 98 | 4.34 | 2/2 | p16 |
| 2026-10-19 | 98 | 4.34 | 2/2 | p18 |
| 2026-10-18 | 98 | 4.34 | 2/2 | p21 |
| 2026-10-17 | 98 | 4.34 | 2/2 | p23 |
| 2026-10-16 | 98 | 4.34 | 2/2 | p21 |
| 2026-10-15 | 134 | 4.34 | 2/2 | p19 |
| 2026-10-14 | 134 | 4.34 | 2/2 | p18 |
| 2026-10-13 | 134 | 4.34 | 2/2 | p12 |
| 2026-10-12 | 134 | 4.34 | 2/2 | p10 |
| 2026-10-11 | 134 | 4.34 | 2/2 | p10 |
| 2026-10-10 | 134 | 4.34 | 2/2 | p11 |
| 2026-10-09 | 134 | 4.34 | 2/2 | p12 |
| 2026-10-08 | 199 | 4.34 | 2/2 | p11 |
| 2026-10-07 | 199 | 4.34 | 2/2 | p10 |
Top water assets
- 67Yellowstone River At Miles City, Mtriver
- 67Froze-To-Death #3reservoir
- 67Yellowstone Riverriver
- 67West Fork Armells Creekriver
- 67Moore #7reservoir
- 67Yellowstone Riverriver
- 67Lambing Shedreservoir
- 67Yellowstone Riverriver
- 67Custer Creekriver
- 67Little Porcupine Creekriver