Mill Sites and Tunnel Sites Beside a Mining Claim

A working mine occupies far more ground than the deposit it exploits. Ore has to be crushed, waste has to go somewhere, and the shop, the assay room and the truck yard need level land that nobody would describe as mineral in character. The General Mining Law answers that need with two instruments that are not mining claims and do not behave like them.

Ground that holds no mineral

A mining claim rests on a discovery. The locator must show a valuable mineral deposit inside the boundaries, and every right the claim confers flows from that fact. A mill site rests on the opposite premise. The land must be nonmineral in character, and the entitlement comes from use rather than from a deposit. That inversion is not a technicality: a mill site located over ground that later proves mineral is vulnerable on that basis alone.

The consequences run through the whole instrument. Because there is no discovery to protect, Congress granted working room rather than a second estate, capping the parcel at five acres and conditioning it on employment for mining or milling purposes. An unused mill site is not merely idle in the way a claim can be idle. It is a site whose only justification has stopped operating, which is why sites are challenged on use far more often than claims are challenged on discovery.

Dependent and independent sites

Two kinds of mill site come out of the same sentence of the statute. The dependent site is attached to a lode or placer claim and holds the works that serve it — the mill, the impoundment, the shop, the water tank. Its validity is tied to the claim it supports, so a challenge that voids the claim ordinarily takes the site with it.

The independent site stands alone. It is available to a person who erects a mill or reduction works to process ore that other people mined, the custom miller who never located a claim at all. Nothing about the independent site depends on any claim, but the use requirement is stricter in effect, because the site has no companion location to lend it purpose. Idle machinery on an independent site invites exactly the inquiry the operator does not want.

Both kinds run through the same location steps as a claim: the ground is marked so the boundaries can be readily traced, a notice is recorded locally under state law, and a copy goes to the federal recording office. The requirement to record with the Bureau of Land Management within the statutory window after location applies to sites in the same terms it applies to claims, and the same conclusive consequences follow a missed filing. Anyone working through the steps that create an unpatented claim is doing the same paperwork for the site beside it.

How many sites may be held

The number question has never been settled comfortably. The statute speaks of a mill site not exceeding five acres and does not state in terms how many may be held by one claimant or how many may attach to a single claim. For a long stretch the Department administered the law on the assumption that an operator could hold the sites its operation genuinely needed. Then a Solicitor's opinion read the Mining Law to permit only one five-acre site for each associated claim, a reading that would have stranded large mills whose footprints were laid out under the older practice. A later opinion withdrew it.

What survives is an unstable answer. The Department has taken both positions in successive opinions, litigation has proceeded on both, and Congress has not amended the section. An operator planning a plant on federal land is therefore planning against an interpretive risk rather than a fixed rule, which is one reason large projects increasingly place their surface facilities on private ground or on land acquired by exchange.

The tunnel site and its line

The tunnel site is the stranger instrument. Someone driving a tunnel to develop a lode cannot see what the working face will cut, and the drafters of the Mining Law wanted to protect that investment against a locator who watched the heading advance and staked the ground above it. The statute gives the tunnel owner the veins or lodes cut on the line of the tunnel, within the stated distance from the face, that were not previously known to exist.

Three limits do most of the work. The right reaches only veins on the line of the tunnel, not everything within a corridor. It reaches only blind veins, so a lode with a known outcrop belongs to whoever located it. And it lapses: the statute treats six months without prosecuting work on the tunnel as abandonment of the right to the undiscovered veins on its line, a forfeiture that operates without any agency finding, in the same self-executing way as the loss of a claim for a missed annual filing.

Comparing the four locations

The four instruments available under the Mining Law are easiest to hold apart by what each one requires and what each one covers.

Holding the site year to year

Sites are maintained on the same calendar as claims. The annual fee statute reaches each unpatented claim, mill site and tunnel site alike, so an operator holding a claim group and three sites pays on six locations rather than three. Small-miner relief is counted the same way, which means the supporting sites consume part of any allowance a claimant is trying to stay within.

The second obligation is use. A mill site that carries no works and serves no operation can be contested, and the government's case is easier than a discovery contest because it turns on visible facts rather than geology and economics. Operators who suspend production without relinquishing sites are well advised to keep the record showing why the ground remains committed to the operation.

Finally, the character of the ground matters at the boundary between these instruments and the rest of federal minerals law. A parcel proposed for a mill site that is underlain by coal, phosphate or another leasable mineral is not open to location at all, and a deposit of ordinary construction rock is disposed of by sale rather than located. Those divisions are covered in the three federal mineral categories and in the treatment of common varieties such as sand and gravel, and they decide the question before any site is staked. Where the surface has been taken into federal trust for a tribe, the land is closed to location entirely, and acquisition proceeds through the process for bringing land into trust status rather than through the Mining Law.