State Highway 251A, also known as SH-251A or OK-251A, is a highway maintained by the U.S. state of Oklahoma. It is 6 miles (9.7 km) long, running from State Highway 16 in Okay, Oklahoma to State Highway 80 north of Ft. Gibson. It runs across the dam of Fort Gibson Lake.

The reason for the number SH-251A is unclear, as there has never been a state highway in Oklahoma with the number 251. The highway was once part of SH-16.

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