Okla. Stat. tit. 47, § 12-216
Every vehicle, including animal-drawn vehicles and vehicles referred to in Section 47-12-101(c), not specifically required by the provisions of this article to be equipped with lamps or other lighting devices, shall at all times specified in Section 47-12-201 of this act be equipped with at least one lamp displaying a white light visible from a distance of not less than five hundred (500) feet to the front of said vehicle, and shall also be equipped with two lamps displaying red light visible from a distance of not less than five hundred (500) feet to the rear of said vehicle or, as an alternative, one lamp displaying a red light visible from a distance of not less than five hundred (500) feet to the rear and two red reflectors visible for distances of one hundred (100) to six hundred (600) feet to the rear when illuminated by the upper beams of head lamps.
Laws 1961, p. 398, § 12-216.