State Highway 321 (SH 321) is a north–south highway in southeastern Texas, starting at US 90 in Dayton and ending at Loop 573 in Cleveland. The route was designated on October 30, 1939. In Cleveland, SH 321 is also known as Houston Street, providing the main street for downtown Cleveland. It is a two lane urban highway with a left turn lane as it travels throughout Cleveland, until roughly 3/4 of a mile northeast of the city limit. From Loop 573, on southward until junction with SH 105, SH 321 is also known as SH 105. In the city of Dayton, it is referred to as North Cleveland Street, passing through residential Dayton as a 4-lane urban highway, before narrowing back down to a 2-lane rural State Highway. SH 321 is part of the eastern Greater Houston area evacuation route, providing a corridor for communities such as Baytown, Kemah, and Pasadena. History Based on Handbook of Texas article about Tarkington Prairie, SH 321 is believed to cover part of the Nacogdoches-Lynchburg trail, being the Old Wells store (as it is referred to on the historical marker) sits along the trail, and SH 321 runs directly in front of the building. Historical markers Old Wells Store, Tarkington Prairie: Roughly southeast of Cleveland where CR 2274 meets SH 321. Burton B. Tarkington, Tarkington Prairie: Roughly southeast of Cleveland in front of the Tarkington Volunteer Fire Department, near CR 2249 and CR 2250 on SH 321. John Cherry, Ryan Cemetery: on SH 321, southeast of Cleveland. Route Description The southern terminus of SH 321 is at US 90 near downtown Dayton. As its travels north, it carries the street name North Cleveland Street, immediately north of US 90 is the Union Pacific Lafayette subdivision, which SH 321 crosses by an underpass under the railroad right of way. FM 1960 terminates at the next intersection, as well as is the southern terminus of FM 1008. SH 321 continues northward through the neighborhoods of Dayton as a 4-lane highway, eventually changing to a 2-lane rural road, then has 2 directional overpasses over the Union Pacific Beaumont subdivision rail line. The eastern terminus of FM 686 occurs just inside the northern edge of Dayton city limit. To the west of SH 321 is 3 Texas Department of Criminal Justice units; Plane State Jail, Henley State Jail, and the Hightower Unit. The road continues north through rural