Description: Black and white aerial photography at 1:12 000 scale of the Regional Municipality of York, Ontario taken in 1970. Digital orthophotography was developed from these images. Orthophotographs combine the image characteristics of the photograph with the geometric qualities of a map. Orthophotography was developed for the entire region. The 1970 digital orthophotographs have a 12cm ground pixel resolution. The 1970 digital orthophotos were subdivided into 1 kilometre by 1 kilometre tiles and were delivered in georeferenced Geotiff image files. The image tiles are horizontally referenced to 6 degree UTM projection and NAD -83 datum. Vertical control datum is referenced to mean sea level as Bench Marks established by the Geodetic Survey of Canada (CGVD28).