SR 271 was a state route that existed from 1930 until 1931 and was located entirely in Williams County.

[1][2] When it was created, it ran along previously unnumbered roads from the village of Montpelier to Bridgewater Township at US 20.

[6][7] The route experienced one more extension, this time at its eastern terminus to act as a spur to the community of Birmingham.

SR 272 was a 1.2-mile-long (1.9 km) state highway located north of downtown Canton.

[2][8] After 1937, the entire route became the northernmost 1.18 miles (1.90 km) of SR 598 following its extension to Huron County.

The route, which was about seven miles (11 km) long, followed the county line for its entire length.

[4][8][18] SR 297 was a short spur route that connected the village of Wayne to US 6 near Bradner.

The route, which had been asphalt-paved for its entire history, was created in 1932 and existed until 1938 when it was absorbed into a lengthened SR 281, the number the road still carries today.

The route when it was created in 1932 only consisted of the segment from its western terminus at SR 4 to the village of New Washington.

[4] In 1938, the route was extended east and north through Gardner and Celeryville to end at US 224 and SR 194 near Willard.

[20][22] SR 309 was a state route that ran from the community of Tunnel Hill to the now-defunct village of Roscoe.

[5] SR 311 was a short spur state route from the village of Brookville to the community of Arlington (within Clay Township) at US 40.

[4][24] As I-70 was built through the area in the early 1960s, the state route was removed from the system though it did feature an interchange with the new Interstate.

[25] Today, the portion of the former state route outside of the village limits is a part of Montgomery County Road 6.

[20][21] SR 333 was a state route running from Dillonvale to Smithfield in Jefferson County.

In downtown Sylvania, the route ended at the intersection of Main and Monroe Streets.

SR 334 was a state route in Carroll and Jefferson Counties in eastern Ohio.

[2] In that year, US 127 was moved onto an alignment closer to the Maumee River (including a concurrency with US 24) leaving SR 336 on the former segment.

[17][27] SR 337 was a short state route along the Ohio River in southeastern Meigs County.

The two-mile-long (3.2 km) spur route ran from the community of Antiquity to Racine at SR 124.

[4][8][18] SR 338 was a state highway along the banks of the Ohio River in southeastern Meigs County.

[16][35][36] SR 346 was a state route in eastern Ohio that became a part of the Appalachian Highway in the 1970s.

[7] The route would be on this alignment for 35 years until 1970 when the Appalachian Highway was opened through southern Ohio.

[21][38] The route was extended to a length of 20.8 miles (33.5 km) running from SR 124 south of Wellston to US 50 southwest of Albany.

The route was only in existence for about three years from 1935 to 1938 when it was fully replaced by SR 212 which was extended from Sherrodsville.