Tunnel Site
A subsurface right-of-way under federal land open to mineral entry, used to reach lode mining claims or to explore for blind veins, up to 3,000 feet long.
Detailed Definition
A tunnel site is a subsurface right-of-way under federal land open to mineral entry. It is used for access to lode mining claims, or to explore for blind or undiscovered veins, lodes, or ledges that are not currently claimed or known to exist on the surface (43 CFR 3832.41).
A tunnel site is not a mining claim. The regulations define a site as either a mill site or a tunnel site, and treat both separately from lode and placer claims (43 CFR 3830.5).
How a tunnel site is located
Under 43 CFR 3832.42, a tunnel site is located by:
- Erecting a substantial post, board, or monument at the face of the tunnel, the point where the tunnel enters cover
- Placing a notice on it that gives the names of the claimants, the actual or proposed course of the tunnel, its height and width, and the course and distance from the face to permanent natural objects or monuments
- Staking the surface along the boundary lines of the tunnel, as state law requires, for 3,000 feet from the face or to the end of the tunnel, whichever is shorter
What it protects
- Blind veins within 1,500 feet. A claimant who located the tunnel site in good faith may acquire the right to any blind vein, lode, or ledge the tunnel cuts, by locating a lode claim on it. The vein must lie within a radius of 1,500 feet from the tunnel axis and must not have been known to exist on the surface (43 CFR 3832.44).
- Protection from other locators. Other parties may not locate lodes within the sidelines of the tunnel and within its 3,000-foot length, unless those lodes appear on the surface or were previously known to exist.
The diligence rule
The claimant must diligently work the tunnel site. A claimant who stops working it for more than 6 consecutive months loses the right to all unknown veins the tunnel may intersect (43 CFR 3832.44).
A tunnel site does not replace a lode claim
A vein discovered within the tunnel site still has to be located separately as a lode claim to obtain the possessory right to it. The date of location of that lode claim is retroactive to the date the tunnel site was located (43 CFR 3832.45).
Recording and fees
A tunnel site is recorded with BLM and the local recording office by the 90th day after location, and it pays the annual maintenance fee of $200, due on or before September 1. A holder under the small miner waiver files a notice of intent to hold for a tunnel site, not an affidavit of assessment work (43 CFR 3835.31).
In the record
A tunnel site recorded with BLM shows that a right-of-way was claimed and kept current. Whether the tunnel was worked continuously, and so whether its protection for blind veins still holds, is not shown by the filing.
Related Terms
Mining Claim
A parcel of federal land on which a claimant asserts the right to possess and develop a valuable mineral deposit under the Mining Law of 1872.
Lode Claim
A mining claim for minerals that occur in veins, lodes, ledges, or other rock in place, limited to 1,500 feet along the vein by 600 feet wide.
BLM (Bureau of Land Management)
The Bureau of Land Management, the Interior Department agency that manages the federal mineral estate and records and maintains unpatented mining claims and sites.
Mill Site
A location of up to 5 acres of nonmineral federal land, not contiguous to a vein or lode, used for activities that support a mining claim or for custom milling.
Locatable Minerals
Minerals on federal land that are acquired by locating a mining claim under the Mining Law, as opposed to leasable minerals and salable mineral materials.