Highway 251 serves as an east–west route in southeast Minnesota between Clarks Grove, Hollandale, Corning, and Lansing Township near Austin.

At its western terminus interchange with I-35, Highway 251 becomes Freeborn County Road 31, also known as Main Street in Clarks Grove.

[1] The route was paved between Clarks Grove and Maple Island and between Corning and U.S. 218 at the time it was marked.

[3][4] This new routing, as well as the remaining gravel portion of the roadway, was paved in 1954 or 1955.

[5][6] Highway 251 originally extended into Clarks Grove proper to intersect U.S. 65 (present-day County Road 45) until Interstate 35 was built.