Mining

Apex

The top or highest point of a vein or lode where it comes closest to the surface, legally significant for extralateral rights.

Detailed Definition

The apex is the top or highest point of a vein or lode where it comes closest to the surface of the earth. Under the Mining Law of 1872, the apex is legally significant because it determines extralateral rights -- the right to follow a vein beyond the vertical side lines of a claim.

Legal significance under 30 U.S.C. 26: - The owner of a lode claim whose boundaries encompass the apex of a vein has the right to follow that vein downward beyond the vertical side lines of the claim - This right extends only between the vertical planes drawn through the end lines of the claim - The apex must lie within the surface boundaries of the claim

Determining the apex: - Geological investigation to identify where the vein reaches its highest point - May require surface and subsurface exploration - Expert testimony often needed in disputes

Apex litigation: Historically, apex disputes were among the most contentious in mining law. Neighboring claim owners frequently litigated over which claim contained the true apex of a vein, as the determination controlled valuable extralateral rights. The Butte, Montana copper mining district was particularly known for extensive apex litigation in the late 1800s and early 1900s.