River WY MT

Lamar River

Wyoming • 44.9282, -110.3943

Hydrography profile Updated Feb 1, 2026

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USGS and NOAA data is for informational purposes. Source notes

Length

48 mi

78 km

Elevation

10,024′ → 5,978′

4,046 ft drop

Stream Order

Large River

Slope

1.59%

83.8 ft/mi

Drainage

654 mi²

1,695 km²

Avg Flow

1,037 cfs

1.7 mph velocity

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 Lamar River

There are 1 USGS water level monitoring stations on Lamar River providing real-time flow and stage data.