Extralateral Rights

Extralateral rights are the right of a lode claim owner to follow a vein, lode, or ledge downward beyond the vertical side lines of the claim, when the top or apex of the vein lies inside the claim. BLM's Glossary of Surveying and Mapping Terms defines them as "the right to mine ore downward along a lode or vein beyond the side lines of a mining location (claim)."

Source of the right

The right comes from 30 U.S.C. 26, which gives lode locators all veins "the top or apex of which lies inside of such surface lines extended downward vertically, although such veins, lodes, or ledges may so far depart from a perpendicular in their course downward as to extend outside the vertical side lines of such surface locations."

Conditions

Under 43 CFR 3832.21(a)(3), a lode claim has extralateral rights when the vein extends through its end lines and:

• The apex "lies on or under the surface within the interior boundaries of the lode claim"; and
• The side lines are "substantially parallel to the course of the vein, lode, or ledge."

The end lines must be parallel. The Mining Law says "The end lines of each claim shall be parallel to each other" (30 U.S.C. 23), and the BLM brochure states that they "must be parallel to qualify for underground extralateral rights."

The end line planes

The right is "confined to such portions thereof as lie between vertical planes drawn downward as above described, through the end lines of their locations, so continued in their own direction that such planes will intersect such exterior parts of such veins or ledges" (30 U.S.C. 26).

Limits

• The right follows the vein only. It does not authorize entry "upon the surface of a claim owned or possessed by another" (30 U.S.C. 26).
• The statute applies to locations "made on any mineral vein, lode, or ledge," and BLM's rules for extralateral rights sit in its lode claim provisions (43 CFR 3832.21(a)).
• BLM's glossary notes that extralateral rights of mining claims located before May 10, 1872 "were determined according to the previous law of 1866 and by miner's local rules and they were not dependent upon parallel end lines," and that "Various States have modified the Federal requirements."

Preserving the right

BLM advises locators to determine the general course of the vein from the point of discovery before marking boundaries (43 CFR 3832.21(a)(4)). An amendment may reposition lode claim side lines to be parallel to the discovered vein "if there are no intervening rights to the land" (43 CFR 3833.21(a)(4)).

Why it matters in mining claim research

Where a vein dips across neighboring ground, the lode claim holding the apex may hold ore beneath an adjoining mining claim. The geometry of each lode claim, the direction of its end lines, and the recorded course of the vein all bear on where extralateral rights may reach.