Its eastern terminus is also at a T-intersection, this time with SR 124 nearly 9.50 miles (15.29 km) southeast of Coolville.

There are no portions of SR 681 that are included within the National Highway System (NHS).

The NHS is a network of highways identified as being most important for the economy, mobility and defense of the country.

This was done to coincide with the coming of the Interstate Highway System to Ohio, which included Interstate 680 (I-680) in the Youngstown area.

Ohio follows a standard that no numerical designation may be duplicated among Interstate, U.S. and Ohio state routes, so to avoid a conflict, SR 680 was re-numbered as SR 681.