River ID MT

Lemhi River

Idaho • 44.9584, -113.6680

Hydrography profile Updated Dec 27, 2025

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USGS and NOAA data is for informational purposes. Source notes

Length

62 mi

99 km

Elevation

5,943′ → 3,913′

2,031 ft drop

Stream Order

Large River

Slope

0.62%

32.9 ft/mi

Drainage

800 mi²

2,073 km²

Avg Flow

327 cfs

1.9 mph velocity

Path to Mouth

830 mi

1,335 km to ocean

Classification

Headwater

Source Stream

Elevation Profile

Water Quality

Data from EPA Water Quality Portal (USGS, EPA, state agencies).

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Data from USGS & NOAA for informational purposes only. Read source and safety notes

Water Level Gauges on Lemhi River

There are 3 USGS water level monitoring stations on Lemhi River providing real-time flow and stage data.