River IL

Willow Branch

Illinois • 39.7359, -90.3321

Hydrography profile Updated Dec 30, 2025

Checking mapped path coverage…

USGS and NOAA data is for informational purposes. Source notes

Length

45 mi

73 km

Elevation

727′ → 510′

216 ft drop

Stream Order

Medium River

Slope

0.09%

4.8 ft/mi

Drainage

46 mi²

120 km²

Avg Flow

-- cfs

1.1 mph velocity

Path to Mouth

1,462 mi

2,353 km to ocean

Classification

Tributary

Mid-reach

Elevation Profile

Water Quality

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

Data from USGS & NOAA for informational purposes only. More