Big Sandy HUC8 10050005
A 2,091 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
71
Moderate
Drought index
110
Moderate
Area in D2+
0%
0% exceptional (D4)
Gauges below normal
0%
of 1 reporting
Median flow
1784%
p89 of record
Water assets
424
0 springs · 190 wells
USGS gauges (6)
- Big Sandy Creek near Havre MT0613950013 cfsp89 · above normal
- Boxelder Creek near Rocky Boy, MT061375702 cfsno long-term record
- Boxelder Cr bl Boneau Reservoir, nr Rocky Boy, MT06137572no readingno long-term record
- Boxelder Cr bl Brown's Res Div, nr Box Elder, MT06137574no readingno long-term record
- Boxelder Creek at Box Elder, MT061375756 cfsno long-term record
- Big Sandy Cr ab Spring Coulee, nr Laredo, MT0613858010 cfsno long-term record
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 110 | 0 | 0/1 | p89 |
Top water assets
- 67Big Sandy Creekriver
- 67Boxelder Creekriver
- 67Big Jugsreservoir
- 67Big Sandy Creek Near Havre Mtriver
- 67Big Sandy Creekriver
- 67Big Sandy Creekriver
- 67Big Sandy Creekriver
- 67Big Sandy Cr Ab Spring Coulee, Nr Laredo, Mtriver
- 67Boxelder Creek At Box Elder, Mtriver
- 67Big Sandy Creekriver