In mining, the right to mine ore downward along a lode or vein beyond the side lines of a mining location (claim). The right is limited to claims which contain the apex of the vein at or very near the surface, which are oriented with the lode line substantially along the vein and which have the end lines substantially parallel. The right does not extend beyond planes passing vertically through the end lines. Extralateral rights of claims filed 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. Various States have modified the Federal requirements.