text: ontario highway 51 king 's highway 51 , commonly referred to as highway 51 , was a provincially maintained highway in the canadian province of ontario that connected highway 3 in eatonville with rondeau provincial park . an earlier designation existed south of orangeville , connecting highway 24 with highway 10 . this iteration was assumed in 1938 , but later renumbered as highway 24 in 1961 . the more recent incarnation of the route number was assumed in 1970 , but then decommissioned in 1997 and transferred to what is now the city of chatham – kent . route description highway 51 was a short connector road that served to link highway 3 to rondeau provincial park . at its southern terminus , the highway began at the entrance gates to the provincial park , proceeding northeast through a small community of recreational cottages . the highway exited the park and turned north onto what is now chatham – kent road 15 . from here the highway progressed straight north to highway 3 , passing through the community of new scotland along the way . trees continue to line both sides of this section of the highway , with farmland sprawling out beyond that . history in 1961 , the section of highway 24 between highway 51 and orangeville was renumbered as highway 136 ; highway 51 was renumbered as highway 24 and the latter signed concurrently with highway 10 north to orangeville . on april 9 , 1970 , the road from eatonville to rondeau provincial park was designated as highway 51 . this iteration of the route remained unaltered until april 1 , 1997 , when it was transferred to kent county , now the city of chatham – kent . it was subsequently designated as chatham – kent road 15 . major intersections the following table lists the major junctions along highway 51 , as noted by the ministry of transportation of ontario . the entire route is located in chatham – kent .