In 1932, an unnumbered state route was created starting near the lake and traveling southeast on mostly dirt roads to US 30 west of Lisbon.

[2][8] At a length of 1.37 miles (2.20 km), the route began at SR 122 west of downtown Eaton, traveled south to the memorial's entrance, went through the site, and ended at itself.

[7] The route was removed from the state highway system in the late 1990s after the memorial's jurisdiction was transferred to the city.

[2][8] The route would not undergo any changes until the mid 1980s when SR 8 was moved off its surface road onto a nearby freeway.

The route stopped appearing in the official state map beginning in 1987 but was included within the 1988 Summit County traffic survey report.

Today, the parts of the former SR 375 outside of the Marietta city limits are Washington County Road 375.

[18] SR 381 was a short-lived state highway connecting Greenville and Ansonia in western Darke County.

The eight-mile-long (13 km) route was created in 1935 but was replaced after 1936 by SR 118 which was greatly expanded from its former terminus in Rockford.

The route, which was six miles (9.7 km) long and located in parts of Violet and Liberty Townships, was created in 1935 along a dirt road.

The route was first designated in 1964 through Defiance when US 24 was moved to an expressway bypass north of the city.

[29] By 1969, as more of US 24 was moved onto the expressway through northwestern Ohio, SR 424 was extended to its full length of about 26 miles (42 km).

[16] The route would remain unchanged until 2008 when all of SR 424 in Defiance County was deleted from the state highway system.

[16] SR 504 was a short 1.29-mile-long (2.08 km) route east of Troy entirely in Staunton Township.

[15][34] Prior to 1937, SR 16 entered downtown Newark from the west on Granville Street staying to the north of the Raccoon Creek.

[19] In 1937, SR 512 was assigned on a straighter route into Newark via Church Street, crossing the creek twice.

[43] SR 524 was a north-south state route in the extreme eastern portion of Ashtabula County.

SR 524 traveled north along the western shore of the Pymatuning Reservoir, never straying more than one and a half miles (2.4 km) from the Pennsylvania state line.

[15][20] The route began near Ghent at US 21 and traveled east into the northern extents of Cuyahoga Falls.

[4][5][15] SR 533 was a 1.81-mile-long (2.91 km) state route entirely in Jefferson Township, Logan County.

The state-maintained route was in existence from 1937 until 2014 when the Ohio Department of Transportation and the Logan County Engineer's Office arranged a jurisdiction swap.

[47] SR 538 was a 2.7-mile long (4.3 km) state highway entirely in Pierpont Township, Ashtabula County.

The route, which existed in 1937 and 1938, connected SR 7 to the Pennsylvania state line where the road continued as PA 198.

[50] SR 543 was a state route in northern Miami and the extreme southern portion of Shelby County.

[5][6] SR 550 was a state route in Pike County that connected Pebble Township and Waverly.

The five-mile-long (8.0 km) route started near Dexter City at US 21 and traveled west and northwest to its eastern terminus at SR 564 in Enoch Township near Middleburg.

After being deleted from the state highway system, the route became a part of Williams County Road 14.

The route it utilized for most of its history from 1939 until 1951 started in Sylvania at US 223 and ran east along Alexis Road to US 25 (Detroit Avenue) in Washington Township.