Texas Natural Resources Code - NAT RES § 11.014. Land Acquired From Oklahoma

(a) Land acquired by the state in Oklahoma v. Texas, 272 U.S. 21 (1926) and subsequent orders of the United States Supreme Court relating to that case, is incorporated into the counties which are adjacent to the land, and the north and south lines of the adjacent counties, Lipscomb, Hemphill, Wheeler, Collingsworth, and Childress, are extended east to the 100th degree of west longitude as it is fixed in the final judgment.

(b) The land acquired from Oklahoma shall become a part of the respective counties as though it were originally included in each county for governmental purposes and shall be assessed for taxes and have taxes collected under the provisions of existing law.