DescriptionThe name of this mountain in the Purcell Range refers to vermiculite, a mineral that exfoliates under heat, making it useful in construction, agriculture, and horticulture, but primarily as insulation and in fire-proofing. It is unknown who named the mountain. The word vermiculite comes from the Latin word vermiculus, “little worms,” which aptly describes the physical reaction vermiculite undergoes when exposed quickly to heat: it expands by exfoliation and creates wormlike pieces. Edward N. Alley discovered the Rainy Creek vermiculite deposit during World War I while looking for vanadium. According to the story, the flame from his candle came into contact with the mica on the mine tunnel’s wall, causing it to swell. Alley worked to develop a market for vermiculite under the name Zonolite. He sold his company in 1934 to the Zonolite Company, which merged with the Universal Zonolite Insulation Company in 1939. They shortened the name to Zonolite Company in 1948. Demand for the mineral during World War II expanded mining operations, and in 1963 W. R. Grace purchased the mine on Vermiculite Mountain and the mill located at the confluence of Rainy Creek and the Kootenai River. By 1980, W. R. Grace employed 200 people. The high concentration of tremolite asbestos in the vermiculite resulted in a public health crisis for workers as well as other residents in the town of Libby. The EPA is currently conducting a massive cleanup at the old mine and mill site, and at contaminated areas in and around Libby. Personal NamesAlley, Edward N.Grace, W. R. Contributing InstitutionMontana Historical Society Library and ArchivesGeolocation[1] Elevation4241 ft. CountyLincoln County
