N.M. Stat. § 4-4-2
[Southern boundary.]
That the boundary line between Mora and Colfax counties be and is hereby
established, to wit: starting at a point on the eastern boundary of New Mexico and about
fifty-three miles south of the northeast corner of New Mexico, and running west through
the center of township twenty-three north from the base line as established by
government survey to the western boundary of the counties of Mora and Colfax.