Natural gas became the primary heating source in 1988, after the plant switched from coal, its primary fuel for over 90 years. The power plant is located next to the former Northern Pacific Railway where rail cars of coal once off-loaded. In January 1958, four visitors from University of Washington, came to inspect Palmer Coking Coal Company’s Landsburg mine in Ravensdale. power plant manager), Gordon Gonberg, plus Jack A. Morris, V.P. Next week, the story of Hubert Kravagna, one of the miners who dug the coal which once kept college students warm.