High Quality Content by WIKIPEDIA articles! Donald Cousens Parkway, regionally designated as York Regional Road 48 and historically known as the Markham Bypass or Markham Bypass Extension, is a regionally maintained arterial bypass of Markham in the Canadian province of Ontario. The route now begins at Copper Creek Drive in Box Grove, south of Highway 407, and travels north to Major Mackenzie Drive (York Regional Road 25). However, it is currently being extended south to meet with the Box Grove Bypass, after which the Donald Cousens Parkway name will be applied south to Steeles Avenue East at the Toronto–York boundary. The route is named for former Markham mayor Don Cousens.