According to the appraisal firm Closser Associates, Pine Mountain was opened in the (late?) 1940’s and has been in continuous operation since. It is now a “regional, weekend resort” meaning, I suppose, that most of their business is on the weekend and most comes from the Midwest. The main ski jump was constructed in 1938 and may pre-date the downhill area.
The Cass City Chronicle printed the “AAA Michigan 1968 Guide to Winter Sports Fun” on Jan. 4, 1968. They listed Pine Mountain, near Ironwood as having 12 slopes and trails, 2 double chairlifts and 8 tows, skating, snow making and grooming and the world’s highest ski jump (referring to the Pine Mountain jumps run by the Kiwanis Club.)
Pine Mountain is still open, now with 27 runs, 2 parks and 5 chairlifts. And the ski jumps are also still open and the Kiwanis Club says they host the best meet in North America annually. The US record of 459′ is still held here.