Okla. Stat. tit. 11 § 37-218
At the time and place named in the notice for proposals to contractors, the municipal governing body shall examine all bids received. Without unnecessary delay, the governing body shall award the contract to the lowest and best bidder. Contractors' bids shall not be held valid longer than forty-five (45) days after the deadline for filing the proposals with the municipality. The aggregate amount of the contract shall not exceed the aggregate estimate of cost submitted by the engineer. The governing body shall have the right to award a contract for all or a portion of the improvement or to reject any or all bids, and to readvertise for other bids when any bids are not, in its judgment, satisfactory. The letting of the contract shall not be complete until the contract is duly executed and the bonds approved.
Okla. Stat. tit. 11, § 37-218