The state highway runs 16.39 miles (26.38 km) from Olivers Shop Road near Hughesville east to MD 765 in Prince Frederick.

The portion of the state highway west of Hughesville was built in the early 1930s, about the same time ferry service began between Benedict and Hallowing Point.

MD 231 begins at an intersection with Olivers Shop Road in the hamlet of Burnt Store in eastern Charles County.

MD 231 heads east as two-lane undivided Burnt Store Road, crossing Gilbert Creek on its way to Hughesville.

In the hamlet of Patuxent, the state highway intersects the southern terminus of MD 381 (Brandywine Road), which heads north into the southeastern corner of Prince George's County.

Before reaching the river, the state highway passes to the north of the village of Benedict, which was the site of the landing of British troops to march toward Washington, D.C., prior to the Battle of Bladensburg during the War of 1812.

After intersecting the northern terminus of MD 508 (Adelina Road), the state highway veers northeast through the village of Barstow, where the highway passes west of a park and ride lot and the Calvert County Fairgrounds before it intersects Barstow Road, which serves the historic homes Cedar Hill and Willow Glenn.

The state highway meets MD 2/MD 4, which run concurrently as Solomons Island Road, on the west side of the county seat.

The state highway reaches its eastern terminus at MD 765 (Main Street), a short distance north of the county courthouse.

[13] State senator Louis L. Goldstein of Calvert County sponsored a bill to construct a bridge between Benedict and Hallowing Point.