Between 1911 and 1979, 139 mines were registered in the Drumheller Valley, of which only 34 were productive for many years. The beginning of the end for the Drumheller mining industry was the discovery of oil at Leduc No. 1 in 1947, after which natural gas became the predominant fuel for heating homes in western Canada. As the demand for coal dropped, mines closed and communities suffered. Some communities, Willow Creek for example, completely vanished while others went from boomtowns to ghost towns.