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.

At its southern terminus, the highway began at the entrance gates to the provincial park, proceeding northeast through a small community of recreational cottages.

[6][7] On April 9, 1970, the road from Eatonville to Rondeau Provincial Park was designated as Highway 51.

[2] This iteration of the route remained unaltered until April 1, 1997, when it was transferred to Kent County, now the City of Chatham–Kent.

[4] The following table lists the major junctions along Highway 51, as noted by the Ministry of Transportation of Ontario.