Tex. Nat. Res. Code § 131.142
Acts 1977, 65th Leg., p. 2622, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.
Amended by Acts 1979, 66th Leg., p. 308, ch. 141, Sec. 41, eff. May 9, 1979;
Acts 1979, 66th Leg., p. 853, ch. 379, Sec. 4, eff. June 6, 1979.