This graph indicates land actively used for oil sands mine operations from 1987 to 2008. By subtracting the amount of land reclaimed (including temporarily reclaimed land and land in various stages of permanent reclamation) from the total amount of land cleared of trees and disturbed, there is a better understanding of the amount of land actively used for oil sands mining operations.
Note that after 2008, this data set is replaced by the Regional Reclamation and Disturbance Tracking by Company data set, which can also be found in the OSM data catalogue.
The data and graph show data as far back as 1987, however both Syncrude Mildred Lake and Suncor Base Operations started prior to that date.