History of King's Highway 51 (#1):
The first King's Highway 51 was a minor local highway which served as a connecting route between Highway 24 and Highway 10 near Caledon. Highway 51 was
first established on April 13, 1938, when the road from Coulterville to Cataract was designated as a new King's Highway. Highway 51 was only 4.5 km in
length, making it one of the shortest provincial highways to ever exist in Ontario. Highway 51 was paved in 1959. In 1962, Highway 24 was rerouted between
Coulterville and Orangeville. The original route of Highway 24 between Coulterville and Orangeville via Alton was renumbered as Highway 136. As a result of
this route renumbering, the route of Highway 51 was absorbed in its entirety into the new route of Highway 24 via Caledon. Another, unrelated Highway 51
existed near Chatham between 1970 and 1997.
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