From the Canadian Horse Racing Hall of Fame:
1907 to 1955 - Dufferin Park
Dufferin Ave., south of Bloor St., and north of Muir St. On west side of Dufferin St., and east of Brock St. Harness racing as well as thoroughbred meets were staged initially by the Toronto Driving Club. Later owned by Abe Orpen and his son Fred. Toronto mayor Sam McBride served as president for many years. The track was founded by the Denison family, who had received grants of land from the Crown because of its outstanding service to King and Country. Charles Leslie Denison built a training course on this location.
Inaugural Meetings: Trotting, August 15, 1907. Thoroughbreds: Sept. 11-12, 1907. Final Meet: November 8, 1955.