Washington Metal Detecting Laws — Research Overview

An orientation to metal detecting and treasure hunting rules in Washington, covering federal land, state land, private property, and who to verify with. This page is general research information, not legal advice. The state-level summaries below are our own category-level orientation and are not sourced to a Washington statute, code section, or agency ruling. Rules change and differ by unit — verify with Washington State Parks before detecting.

Public and federal land in Washington [UNSOURCED SUMMARY — confirm with the managing federal unit]: BLM and most national forests permit detecting outside designated sites. Federal land is also governed nationally by the Archaeological Resources Protection Act (ARPA) and the Antiquities Act, which prohibit disturbing archaeological resources over 100 years old without a permit.

State land in Washington [UNSOURCED SUMMARY — confirm with Washington State Parks]: Washington state parks generally prohibit detecting.

Permits, permissions, and best practices in Washington [UNSOURCED SUMMARY]: Many tribal lands require permits; check with each nation. Always carry written landowner consent for private ground and photograph the permission document.

Terrain and productive regions in Washington: Cascade rainforest, basin desert, and coastal islands. Top areas to research include Lewis River corridor (Cooper money), Cascades, San Juan Islands.

Documented cases relevant to legal research in Washington: D.B. Cooper money (1971, partially recovered 1980); Lost gold of Mount Si; Hudson's Bay Company caches — legal status of any recovered items depends on land ownership at the moment of discovery.

Federal rules that apply in Washington regardless of state law: ARPA (16 U.S.C. 470aa-470mm) protects archaeological resources 100 years or older on federal and Native American land; NAGPRA (25 U.S.C. ch. 32) governs Native American remains and cultural items; and the National Park Service prohibits metal detector use in park areas under 36 C.F.R. 2.1. Treasure trove and lost-property doctrine are set by state law and are not summarized here.

Verify with the governing agency in Washington: Washington State Parks (https://www.parks.wa.gov/). Archaeological designations and permitting: the Washington State Historic Preservation Office, listed in the NCSHPO directory at https://ncshpo.org/. Federal land: Bureau of Land Management, National Park Service, and USDA Forest Service.