The Libby Asbestos site is located in Libby in Lincoln County, Montana. In the early 1920s, the Zonolite Company began vermiculite ore mining operations in Libby. Vermiculite from the Libby mine, bought by W.R. Grace in 1963, was contaminated with a toxic and highly friable form of asbestos called tremolite-actinolite series asbestos, often called Libby amphibole asbestos (LA). LA has been observed in air (indoor and outdoor ambient), vermiculite insulation and bulk materials, indoor dust, soil, water, animal and fish tissue and various other media in Libby. Historic or continuing releases of LA from mine?related materials could be serving as a source of ongoing exposure and risk to current and future residents and workers. Investigation and cleanup of the site is ongoing.