Highway 79 was designated as a provincial highway from 1937 to 1997. The highway served the counties of Lambton and Kent County. Kent County later became known as Chatham-Kent when the City of Chatham and the County of Kent were almalgamated by a decision of the Ontario government.
>p Highway 79 ran from Highway 2 from south of Bothwell to Highway 21 at Northville (near Port Franks). In 1997 the highway was downloaded to the municipalities of mentioned above at a time (1997/1998) when a large number of provincial highways or sections of provincial highways were being downloaded to lower tier governments across the province, particularly in southern Ontario, as the highways had been deemed not significant to the provincial highway system at that time.