Arrow HUC8 10040102
A 3,296 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
62
Moderate
Drought index
116
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
—
no gauges reporting
Median flow
—
of normal for the date
Water assets
1,023
444 springs · 259 wells
USGS gauges (0)
No active discharge gauges in this sub-basin.
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 116 | 0 | — | — |
Top water assets
- 69Lone Tree Creekriver
- 69Lone Tree Creekriver
- 69Lone Tree Creekriver
- 67Cottonwood Creekriver
- 67Flat Creekriver
- 67Arrow Creekriver
- 67Arrow Creekriver
- 67Surprise Creekriver
- 67McCarthy Creekriver
- 67Arrow Creekriver