Every mark on this map is a district that carries recorded mineral occurrences in the state's own database. Size is how much is recorded there. Colour is how much of it is the material we actually certify.
The state's own live claims service reports zero active exploration claims and zero active stakes. All 4,588 recorded claim areas are historical or expired. Ground is open. Claiming is possible but permits, minimum size and lease rules apply.
Levels are built from the Maine Geological Survey / USGS public mineral-occurrence database. Values are town-level aggregates: a mark sits at the mean position of that town's recorded occurrences, so it does not point at any single site.
We publish no mine names, no individual dig locations and no claim holders. Those are public records, but a one-person operation's actual ground is not something we hand out. Occurrence records are historical; presence of a record is not a promise of material, and nothing here is a reserve estimate or an invitation to trespass.
Permits, claim sizes, staking requirements and lease rules all apply before anyone may work ground. See the scouting page for the actual state rules and costs.
A record means an occurrence was documented at some point — often decades ago. It does not mean material is still there, reachable, or on land you may work.
Beryl, gemstone, uranium, tantalum, apatite and tourmaline count for more than bulk feldspar and mica, because those are the ones that become certified specimens rather than tonnage.
Maine requires an exploration permit for state land, a 20-acre minimum claim, four posted corners and marked lines — and a mining lease with state royalties to remove anything to market. State parks are off limits entirely.