30 U.S. Code § 41 - Intersecting or crossing veins
Where two or more veins intersect or cross each other, priority of title shall govern, and such prior location shall be entitled to all ore or mineral contained within the space of intersection; but the subsequent location shall have the right-of-way through the space of intersection for the purposes of the convenient working of the mine. And where two or more veins unite, the oldest or prior location shall take the vein below the point of union, including all the space of intersection.
Source(R.S. § 2336.)
R.S. § 2336 derived from act May 10, 1872, ch. 152, § 14,17 Stat. 96.