Okla. Stat. tit. 47, § 11-402
The driver of a vehicle intending to turn to the left shall yield the right-of-way to any vehicle approaching from the opposite direction which is so close thereto when initiating such turn as to constitute an immediate hazard.
Laws 1961, HB 556, p. 379, § 11-402, eff. September 1, 1961; Amended by Laws 2010, HB 2322, c. 228, § 4, eff. November 1, 2010 (superseded document available).