Ohio State Route 540
|Maintained by ODOT|
|Length:||8.72 mi (14.03 km)|
|Existed:||1937 – present|
|West end:||US 68 / SR 47 in Bellefontaine|
|US 33 in Bellefontaine|
|East end:||SR 292 near West Mansfield|
State Route 540 (SR 540, OH 540) is an east–west state highway in the western portion of the U.S. state of Ohio. SR 540 has its western terminus in downtown Bellefontaine at a signalized intersection with U.S. Route 68 (US 68) and SR 47. Its eastern terminus is at a T-intersection with SR 292 approximately 3.50 miles (5.63 km) southwest of West Mansfield.
Route description 
The entirety of SR 540 is situated within the eastern portion of Logan County. There are no stretches of SR 540 that are included within the National Highway System (NHS). The NHS is a network of routes identified as being most important for the nation's economy, mobility and defense.
|This section requires expansion. (March 2011)|
The SR 540 designation was assigned in 1937. Originally, the highway was routed along the portion of its current alignment from its intersection with County Road 25 (CR 25) about 2 miles (3.2 km) east of Bellefontaine to its present eastern terminus at SR 292. In 1937, CR 25, along with SR 540 between CR 25 and downtown Bellfontaine, was a part of SR 32, which would become US 33 one year later.
By 1964, US 33 was routed onto its current alignment around the east side of Bellefontaine. Consequently, the former portion of US 33 from the previous western terminus of SR 540 west into downtown Bellefontaine became a westward extension of SR 540 which resulted in the highway taking on its present shape.
Major intersections 
The entire route is in Logan County.
|Bellefontaine||0.00||0.00|| US 68
|Western terminus at signalized intersection|
|1.61||2.59||US 33||Diamond interchange|
|Jefferson Township||5.71||9.19||SR 533 north||T-intersection marking southern terminus of SR 533|
|Perry Township||8.72||14.03||SR 292||Eastern terminus at T-intersection|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- Ohio Department of Highways (1936) (MrSID). Official Ohio Highway Map (Map). Cartography by ODOH. http://www.dot.state.oh.us/Divisions/TransSysDev/Innovation/prod_services/Documents/StateMaps/otm1936a.sid. Retrieved 2011-03-24.
- Ohio Department of Highways (1937) (MrSID). Official Ohio Highway Map (Map). Cartography by ODOH. http://www.dot.state.oh.us/Divisions/TransSysDev/Innovation/prod_services/Documents/StateMaps/otm1937a.sid. Retrieved 2011-03-24.
- Ohio Department of Transportation. "Technical Services Straight Line Diagrams". Retrieved 2010-04-07.
- Federal Highway Administration (December 2003) (PDF). National Highway System: Ohio (Map). http://www.fhwa.dot.gov/planning/nhs/maps/oh/oh_Ohio.pdf. Retrieved 2011-03-30.
- Ohio Department of Highways (1938) (MrSID). Official Ohio Highway Map (Map). Cartography by ODOH. http://www.dot.state.oh.us/Divisions/TransSysDev/Innovation/prod_services/Documents/StateMaps/otm1938a.sid. Retrieved 2011-03-24.
- Ohio Department of Highways (1962) (MrSID). Official Ohio Highway Map (Map). Cartography by ODOH. http://www.dot.state.oh.us/Divisions/TransSysDev/Innovation/prod_services/Documents/StateMaps/otm1962a.sid. Retrieved 2011-03-24.
- Ohio Department of Highways (1964) (MrSID). Official Ohio Highway Map (Map). Cartography by ODOH. http://www.dot.state.oh.us/Divisions/TransSysDev/Innovation/prod_services/Documents/StateMaps/otm1964ar.sid. Retrieved 2011-03-24.