The following paper outlines the evolution of mining methods for oil sand mines, which resulted from unexpected problems faced during the initial phase of mine operations. It also discusses the present efficiency and selected performance data of these mines. Commercial production of synthetic crude oil from the Athabasca oil sands in Alberta was initiated by Great Canadian Oil Sands, Ltd. (now Suncor, Inc. ) in 1967. at present, there are two plants, producing together close to 30,000 m³ of crude per day. Both plants mine oil sand by open-pit methods and transport it to the extraction plant, located at the mine-mouth, for extraction of bitumen.