 HBOG expanded during the 1940s and 1950s, and in 1960 began shipping Canadian crude through a new link to the Glacier pipeline and on to the refinery in Billings, Montana.The company became the sixth-largest Canadian oil producer in 1967.In 1973, HBOG acquired a 35 per cent stake in Siebens Oil and Gas, and, in 1979, it divested that interest.