Entering from West Virginia at Marietta via the Marietta–Williamstown Interstate Bridge, I-77 passes through rolling Appalachian terrain.

The interchange with I-70 at Cambridge was noted on the cover of the 1969 Ohio Department of Highways (ODOT) official highway map as being the "World's Largest Interchange", covering over 300 acres (120 ha) of land.

I-77 is also known as the "Vietnam Veterans Memorial Highway" in Ohio,[3] and the Willow Freeway in Greater Cleveland.

The part of I-94 from Detroit, Michigan, northeast to Port Huron was originally planned as I-77 in 1957; the current I-77 was I-79.

[citation needed] Initially, US Route 21 (US 21) traveled from Marietta to Cleveland.