The discovery need not be on the surface and may be made underground. In the case of blanket (horizontal) veins, the vein may be wider than the claim and discovery can be made anywhere within its boundaries. A discovery showing value and/or marketability may be anywhere within the claim. The discovery may be on the end line of a claim, but a single discovery cannot support more than one claim.
A discovery may be lost by the patenting of a junior claim in conflict, in which case a new discovery is required.
A claim cut in two by a non-mineral patent requires a discovery on each portion of the claim.
A claimant is entitled to possession as against third parties as long as he is diligently engaged in trying to make a discovery.
2–2 Discovery Work: 43 C.F.R. 3841.3–2 states:
“The claimant should, therefore, prior to locating his claim, unless the vein can be traced upon the surface, sink a shaft or run a tunnel or drift to a sufficient depth therein to discovery and develop a mineral-bearing vein, lode or crevice; should determine, if possible, the general course of such vein in either direction from the point of discovery, by which direction he will be governed in marking the boundaries of his claim on the surface.”
Except for the foregoing, the matter of discovery work is left to State law. The general requirement was that the vein (deposit) be disclosed to a depth of ten feet, or deeper if necessary, in a shaft, cut or tunnel. In recent years the tendency is away from requiring discovery work. This was brought about largely through the destruction of the surface by bulldozers digging needless pits or cuts on uranium claims in order to satisfy State law.
Drill holes have also been substituted for the usual shaft, cut or tunnel. In some cases the filing of maps has been substituted for discovery work.
The statutory requirements for each State are given in Chapter I. This chapter and the statutes themselves should be checked for current requirements.
In any event, a discovery point (usually marked by a discovery monument, bearing a notice) should be selected by the claimant from which to recite the dimensions of his claim. If a discovery is made underground, the discovery work requirement is usually met by driving a drift or raise, or sinking a winze on the vein, for ten feet in length; the discovery point is then marked on the surface, with the dip of the vein, if any, projected to the surface.