Ontario Highway 509 History - The King's Highways of Ontario

Secondary Highway 509 was a local highway in the County of Frontenac that provided access from Highway 7 to a number of small communities located northwest of Sharbot Lake. Highway 509 was originally designated by an Order-in-Council dated May 9, 1956, and was first depicted on a Preliminary Route Plan prepared by the Department of Highways of Ontario (DHO) in June 1956. Initially, the route of Highway 509 only extended north from Highway 7 for approximately 5 3/4 miles (9 km) via the Sharbot Lake-Lavant Road to Clarendon Station. Additional sections of Highway 509 to Snow Road Station and Plevna were designated later. According to Official Road Bulletins issued by the DHO in the late 1950s, Highway 509 was paved for its entire length by 1957.

The first extension of Highway 509 took place in 1959. Preliminary Assumption Plans were prepared by the DHO for the Townships of Oso and Palmerston dated May 1957 and May 1959, respectively, which illustrated the proposed extension of Highway 509 via the Sharbot Lake-Lavant Road. The proposed highway began at Clarendon Station located just south of the Oso-Palmerston Township Boundary and extended northerly for approximately 6 miles (9.5 km) to Snow Road Station. Both plans were registered on June 1, 1959, and the route was formally designated as Highway 509 by an Order-in-Council dated July 9, 1959. Following the 1959 extension of Highway 509 to Snow Road Station, the highway's total length was approximately 12 miles (19 km). A mulch pavement was laid along Highway 509 from Clarendon Station to Snow Road Station in 1962.

During the late 1970s, a significant extension of Highway 509 took place. The Ministry of Transportation and Communications (MTC) acquired jurisdiction and control over the Ompah and Plevna Road from Snow Road Station northwesterly to Plevna as a new Secondary Highway. A Preliminary Assumption Plan was prepared by the MTC dated May 26, 1977, which illustrated the proposed extension of Highway 509 from the northern end of the existing highway at Snow Road Station northwesterly to the eastern terminus of Highway 506 in Plevna. This plan was registered on June 6, 1977, and the highway was subsequently designated as a Secondary Highway by an Order-in-Council dated July 20, 1977. The Highway 509 Extension from Snow Road Station to Plevna was shown with a paved surface on the 1978-1979 Official Ontario Road Map. Following the extension of the highway to Plevna in 1977, Highway 509 had grown to a length of approximately 33 miles (53 km).

A handful of small diversions were built for Highway 509 over the years. A small diversion was constructed about 1/2 mile south of Clarendon Station in 1966. A second diversion was built around Clarendon Station in 1973, which resulted in a bypassed loop of Highway 509 (known today as Clarendon Road and School House Road). The proposed Clarendon Station Diversion was initially designated as a Secondary Highway by an Order-in-Council, effective August 30, 1967. Rather than transfer the old loop of Highway 509 over to municipal control, the province retained ownership over the old highway's route until the 1990s. During reconstruction of Highway 509 in the late 1960s, a small corner diversion was constructed at Antoine Creek just south of Snow Road Station. A section of Antoine Creek itself was realigned so that it no longer had to pass below the highway, rather than cross the highway twice. The former alignment of Highway 509 through the sharp corner was legally closed to traffic, effective June 17, 1983.

Highway 509 remained in the provincial highway system up until the late 1990s. Jurisdiction over the highway was transferred from the province to the Townships of North Frontenac and Central Frontenac, effective January 1, 1998. Former Highway 509 is now known as North Frontenac Road 509 and Central Frontenac Road 509. Unless posted otherwise, the speed limit on Highway 509 is 80 km/h (50 mph). Services are available on Highway 509 in Plevna, Ompah and in nearby Sharbot Lake along Highway 7.