Historical Maps & Aerial Imagery

County atlases including townships of Markham and Vaughan (McGill University)

Tremaine map of York County, 1860 (University of Toronto Libraries)

Aerial images over Thornhill - ca.1930-1988. (Thornhill Archives)

Built to Last: Heritage Properties from York County to York Region [Historical description of York County & York Region with maps] (York Region, 2017). 

City of Toronto Aerial Images, 1947-1992 [many years of coverage extend into the Thornhill area].

York Region in 1860 vs Today - slide map (York Region)

York Region in 1970 vs Today - slide map (York Region)