Lower Clark Fork HUC8 17010213
A 6,052 km² sub-basin of the Pacific Northwest region in ID, 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
61
Moderate
Drought index
212
Severe
Area in D2+
12.15%
0% exceptional (D4)
Gauges below normal
40%
of 5 reporting
Median flow
88%
p36 of record
Water assets
1,031
23 springs · 204 wells
USGS gauges (5)
- LIGHTNING CREEK AT CLARK FORK ID123921551 cfsp5 · much below normal
- Prospect Creek at Thompson Falls MT1239070050 cfsp22 · below normal
- Clark Fork near Plains MT123890007,860 cfsp36 · normal
- Thompson River near Thompson Falls MT12389500162 cfsp37 · normal
- CLARK FORK RIVER BELOW CABINET GORGE DAM ID123919508,710 cfsp56 · normal
Recent conditions
| Date | DSCI | D2+ % | Gauges low | Flow pct |
|---|---|---|---|---|
| 2026-09-07 | 212 | 12.15 | 2/5 | p36 |
Top water assets
- 69Bighorn Creekriver
- 69Bighorn Creekriver
- 67Cherry Creekriver
- 67Cabinet Gorgereservoir
- 67Noxon Rapidsreservoir
- 67Clark Fork Near Plains Mtriver
- 67Thompson River Near Thompson Falls Mtriver
- 67West Fork Combest Creekriver
- 67Clark Fork River Below Cabinet Gorge Dam Idriver
- 67Graves Creekriver