This property has a documented history as a industrial and manufacturing facility going back to 1885. Historical insurance policies issued during those prior operations and through 1986 could fund a cleanup.
The Bonanza Mine, located in the Bossburg Mining District of Stevens County, has been documented as an industrial mining operation since its discovery in 1885, producing lead, silver, zinc, and copper on a scale that accounted for nearly one-fifth of all lead and one-sixth of all silver ever mined in Stevens County. Primary mining operations concluded in 1953, the mill continued processing ore through 1967, and decommissioning occurred in 1973. A time-critical Removal Action in October 2002 capped an estimated 60,000–70,000 cubic yards of exposed tailings at the Bonanza mill site and included shoreline stabilization and drainage reconfiguration; in 2007, approximately 41,500 cubic yards of waste rock from an upper dump was transported by Stevens County for use as road ballast but subsequently removed and returned to the site after toxicity concerns were identified. The site remains in the Awaiting Cleanup stage, with comprehensive remediation still ahead. That history could support an insurance cost recovery claim against carriers who issued insurance policies 40+ years ago.
Why Historical Insurance Policies May Be Accessible
Pre-1986 Commercial General Liability (CGL) policies were occurrence-based and did not contain an effective pollution exclusion in Washington. If contamination occurred while those policies were active, those historical insurance carriers may still have a legal obligation to fund the cleanup costs, even if the business closed or the property changed hands.
Mining and milling operations at the Bonanza Mine spanned from 1885 through 1967 — a century of industrial activity that predates 1986 by decades and falls squarely within the era when occurrence-based Commercial General Liability policies were the industry standard and carried no effective pollution exclusion. The contamination here originates from historical waste rock and mill tailings — the kind of gradual, long-running industrial release those pre-1986 policies were written to address. Remediation expenditures already incurred — emergency tailings capping, shoreline stabilization, and waste rock retrieval — together with the comprehensive cleanup still to come, represent costs that historical carriers whose policies were in force during those operational decades may be obligated to fund.
Restorical's role is to locate viable historical policies, determine whether a successful coverage claim is possible, and assist our clients and their legal counsel to obtain insurance coverage. Restorical then manages the claim, including accounting, to ensure the cleanup is funded in a timely manner.
What We Look For
- Historical insurance policies (pre-1986)
- Policy numbers, carrier names, and coverage periods
- Connection between contamination timing and policy period
- Evidence linking cleanup obligation to insured activity
What We Deliver
- Historical Coverage Chart
- Trigger Analysis & Property/Policy Nexus
- Coverage strategy with recommendations
- Insurance funding for your remediation
- Claims Management & Forensic Accounting
The Restorical Proven Process
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Contact UsThis analysis is preliminary and based on publicly available records. Restorical Research is not a law firm and does not provide legal advice.


