 The ore horizons are known locally as amygdaloids, after the amygdaloidal-shaped gas bubbles in the lavas that filled with minerals.Copper Range shut down the Champion mine, its last operating native copper property, in 1967.Copper Range spun off its wholly owned subsidiary White Pine Copper Co., which in 1955 opened the White Pine mine at the south end of the copper belt, at White Pine, Michigan, Ontonagon County.