Rainy Creek Operation

The Rainy Creek Operation was the W.R. Grace & Company vermiculite mining and milling complex near Libby, Montana. From 1963 until the mine's closure in 1990, Grace extracted vermiculite ore that was heavily contaminated with Libby amphibole asbestos, processing it on-site and shipping the concentrate to expansion plants across North America. The site is now one of the most extensive asbestos contamination zones in U.S. history.

Origin

The operation takes its name from Rainy Creek, a tributary of the Kootenai River that drains the vermiculite deposit in the Cabinet Mountains of northwest Montana. Commercial mining began there under the Zonolite Company in the 1920s; W.R. Grace acquired Zonolite in 1963 and continued operations under the Rainy Creek name until 1990.

Significance in Asbestos Context

For patients and families with any tie to Libby, Montana, the Rainy Creek Operation is often the central exposure source in their case. Workers at the mine and mill, their family members exposed to dust brought home on clothing, and Libby-area residents exposed to airborne contamination and to vermiculite used in gardens, driveways, attics, and ball fields have all developed mesothelioma, lung cancer, asbestosis, and pleural disease at extraordinary rates. Internal Grace documents, many now public, show the company knew of the asbestos contamination and worker disease for decades before disclosure, which is critical evidence in personal injury claims, the Libby Medical Plan, and federal cleanup actions. Exposure to Libby amphibole (a mixture including tremolite, winchite, and richterite) is now formally recognized by the EPA as causing disease, and the area was the first-ever Public Health Emergency declared under CERCLA in 2009.

Example Sentence

Her father worked at the Rainy Creek Operation for eleven years in the 1970s, and her own mesothelioma was traced to washing his contaminated work clothes.

Related Terms

Libby Amphibole, W.R. Grace & Company, Zonolite, Vermiculite, Take-Home Exposure, Tremolite Asbestos

Notes

• If you, a parent, spouse, or sibling worked at the Libby mine or mill, gather employment records, union records, and W-2s; these establish the exposure timeline that drives both medical screening eligibility and legal claims.
• Libby-area residents and former workers may qualify for the Center for Asbestos Related Disease (CARD) screening program in Libby and for benefits under the Libby Medicare provisions of the Affordable Care Act. Ask your physician for a referral.
• Preserve any household items, photographs, or documentation showing vermiculite use at home (insulation, garden amendments, driveways), as these support take-home and ambient exposure claims.
• Claims involving Rainy Creek exposure typically proceed through the W.R. Grace asbestos personal injury trust established after Grace's 2001 bankruptcy; an attorney experienced with that trust can explain filing requirements and evidence standards.