Secondary Highway 538, commonly referred to as Highway 538, is a provincially maintained highway in the Canadian province of Ontario. The highway is 5.6 kilometres (3.5 mi) in length and follows an older alignment of Highway 17 east of Blind River and near the village of Algoma Mills, between the Canadian Pacific Railway tracks and the shoreline of the North Channel of Lake Huron, while the present Highway 17 runs north of the railway tracks. The route was designated in 1956 and has remained unchanged since.
Secondary Highway 534, commonly referred to as Highway 534, is a provincially maintained secondary highway in the Canadian province of Ontario. The route begins at the entrance to Restoule Provincial Park and ends near Highway 11 in Powassan. The route provides access to several communities which lay south of Lake Nipissing. Between those communities, the highway travels mostly through thick boreal forest. It was assumed in 1956, following its present course and remaining unchanged since. It is a lightly travelled route accommodating, on an average day, no more than 830 vehicles.
Secondary Highway 510, commonly referred to as Highway 510, is a provincially maintained highway in the Canadian province of Ontario. The highway is 2.4 kilometres (1.5 mi) in length, connecting Highway 520 in Magnetawan with Highway 124. It was established in 1956, along with most of the secondary highway system in the province, and is little changed since then.
Secondary Highway 522, commonly referred to as Highway 522, is a provincially maintained highway in the Canadian province of Ontario. The highway is 109.6 kilometres (68.1 mi) in length, connecting Highway 69 near Cranberry with Highway 11 at the community of Trout Creek. Highway 522 serves as the only link between these two routes south of Highway 17 and north of Highway 124. It is often used to access Grundy Lake Provincial Park, a popular camping area for northbound travellers.
Secondary Highway 518, commonly referred to as Highway 518, is a provincially maintained secondary highway in the Canadian province of Ontario. Highway 518 spans 72.7 kilometres (45.2 mi) between Parry Sound and Kearney. It serves as one of the many links between Highway 400 and Highway 11. The highway was assumed in 1956, and has remained generally unchanged since, aside from being truncated slightly at both ends.
Secondary Highway 525, commonly referred to as Highway 525, is a provincially maintained secondary highway in the Canadian province of Ontario. It is a short, remote secondary highway that links Highway 596 to the Wabaseemoong First Nations reserve. It is the second-westernmost secondary highway in the province, Highway 673 being the first. The route was commissioned by 1982 along what was formerly Highway 596; a former use of the route number existed between 1956 and 1973 in Gravenhurst.
Secondary Highway 526, commonly referred to as Highway 526, is a provincially maintained secondary highway in the Canadian province of Ontario. It is a short and lightly travelled route that connects Highway 69 with the community of Britt.
Secondary Highway 532, commonly referred to as Highway 532, is a provincially maintained secondary highway in the Canadian province of Ontario. The route connects several mining and milling towns in Unorganized Algoma District, notably Searchmont. The route is remote, ending at a mine access road 14.2 kilometres (8.8 mi) north of Highway 556, its southern terminus.
Secondary Highway 531, commonly referred to as Highway 531, is a provincially maintained secondary highway in the Canadian province of Ontario. It connects Highway 17 east of North Bay with the community of Bonfield. The 3.5-kilometre (2.2 mi) route was established in 1956, and has remained the same since then. It passes through a forested area and has several private residences located along its length. Aside from Maple Road, its southern terminus, and Highway 17, its northern terminus, Highway 531 encounters no roads along its length.
Secondary Highway 654, commonly referred to as Highway 654, is a secondary highway in the Canadian province of Ontario. The highway is 23.1 kilometres (14.4 mi) in length, connecting Highway 534 south of Nipissing with Highway 11 in Callander. The route was designated in 1964, and has remained unchanged since then. It is sparsely travelled, but paved throughout its length.
Secondary Highway 529A, commonly referred to as Highway 529A, is a provincially maintained secondary highway in the Canadian province of Ontario. Located within Parry Sound District, the highway is a short spur of Highway 529, extending from Manbert to Bayfield Inlet.
Secondary Highway 528A, commonly referred to as Highway 528A, is a provincially maintained secondary highway in the Canadian province of Ontario. The 5.1-kilometre (3.2 mi) spur route links the community of Wolseley Bay in French River with several lodge resorts to the southeast. The route ends suddenly within viewing distance of the French River, where a driveway continues into a lodge.
Secondary Highway 539A, commonly referred to as Highway 539A, is a provincially maintained secondary highway in the Canadian province of Ontario, located within Nipissing District. Commencing at a junction with Highway 539 in the community of River Valley, the highway extends northwesterly for 13.1 kilometres (8.1 mi) to a point near where the Sturgeon River crosses the boundary between Nipissing and Sudbury District. At this point, the roadway turns northward and continues as Highway 805.
Secondary Highway 618, commonly referred to as Highway 618, is a provincially maintained secondary highway in the Canadian province of Ontario. It connects Olsen Mine and Madsen with the northern terminus of Highway 105 in the town of Red Lake. The 11.7-kilometre (7.3 mi) route was established in 1956, and has remained the same since then. It passes through a remote forested area, and encounters no communities of any significance outside of Red Lake. The route was assumed by the Department of Highways, predecessor to today's Ministry of Transportation of Ontario, in 1956, along with many other secondary highways in Ontario. The route has remained unchanged since then.
Secondary Highway 606, commonly referred to as Highway 606, was a provincially maintained secondary highway in the Canadian province of Ontario. This short spur connected Highway 17 with the community of Markstay and was only 1.5 kilometres (0.93 mi) long. Highway 606 was located entirely within what is now the Municipality of Markstay-Warren in Sudbury District.
Secondary Highway 541, commonly referred to as Highway 541, was a provincially maintained secondary highway in the Canadian province of Ontario. The highway connected Highway 17 in Sudbury with the community of Skead on the southern shores of Lake Wanapitei, passing through the community of Garson en route. Within the urban region of Sudbury, the highway served to access Sudbury Airport. The designation was applied in 1956, along with many of the secondary highways in Ontario. The province transferred responsibility for the route shortly after the creation of the Regional Municipality of Sudbury in 1973. Highway 541 is now known as Sudbury Municipal Road 86, following Falconbridge Highway and Skead Road.
Secondary Highway 541A, commonly referred to as Highway 541A, was a provincially maintained secondary highway in the Canadian province of Ontario. This short 3.2-kilometre (2.0 mi) spur connected Highway 541 north of Garson with the community of Falconbridge.
Secondary Highway 545, commonly referred to as Highway 545, was a provincially maintained secondary highway in the Canadian province of Ontario. This 33.9-kilometre (21.1 mi) highway connected Highway 541 at Bailey Corners near Garson with the now-abandoned community of Milnet, passing through Hanmer and Capreol. It followed what is now Municipal Road 85, Municipal Road 84, and Milnet Road. The route featured a concurrency with Highway 69 between Hanmer and Capreol.
Secondary Highway 536, commonly referred to as Highway 536, was a provincially maintained secondary highway in the Canadian province of Ontario. This highway connected Highway 17 near Lively with Wellington Street at the Creighton Mine. Highway 536 followed most of what is now Municipal Road 24, north from Greater Sudbury Road 55. The route existed from 1956 until the formation of the Regional Municipality of Sudbury in 1973.
Highway 522 at Farley's Corners 
Highway 534 near Restoule 
