Okla. Stat. tit. 68, § 1106

The provisions of the gross production tax law in respect to refunds of such tax on the production derived from restricted Indian lands and lands owned by the United States, the state, counties, cities, towns and school districts, and therefore exempt from taxation, shall apply to petroleum excise tax on such exempt interest in said production from said lands. Laws 1965, c. 442, § 2.