Tex. Natural Resources Code § 21.079: LAND IN MORE THAN ONE ZONE.

If a tract of land to be defined by a single description extends from one zone into another of the coordinate zones, the positions of all points on its boundaries may be referred to by either of the zones, the zone which is used being specifically named in the description.

Acts 1977, 65th Leg., p. 2360, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977. Amended by Acts 1987, 70th Leg., ch. 616, Sec. 9, eff. Sept. 1, 1987.