Okla. Stat. tit. 11 § 35-101
Any municipality owning or operating its own system of generating or distributing energy or utilities, and any municipality engaged in the distribution of energy or utilities, may extend its lines, mains, and channels together with necessary appurtenances beyond the corporate limits of the municipality. Such municipality may acquire, erect, construct and own all necessary poles, wire, lines, pipelines, mains, channels together with necessary appurtenances, apparatus and substations, and acquire rights-of-way, and do all other things necessary and proper in carrying on the business outside of the corporate limits of the municipality to the same effect as it may now do within the corporate limits of the municipality. Such municipality may construct or acquire lines, pipelines, mains or channels together with necessary appurtenances by purchase or otherwise and may sell such service to any person, firm or corporation outside of the limits of the municipality.
Okla. Stat. tit. 11, § 35-101