Okla. Stat. tit. 19, § 19-1239: Awarding of contracts - Excessive costs

At the time and place specified in the notice to contractors,

the board of county commissioners shall examine all bids received

and, without unnecessary delay, award the contract to the lowest and

best bidder, who will perform the work and furnish the materials

which have been selected, and perform all the conditions imposed by

the board, as prescribed in the resolution for the work or

improvement and notice for proposals. The aggregate amount of the

contract shall not exceed the final estimate of cost submitted by

the engineer for the improvement as provided in Section 1238 of this

title. In the event of any excess in cost over said engineer's

estimate, the excess shall be void and no assessments for such

excess levied. The board shall have the right to award a contract

for all or a portion of such improvement or to reject any or all

bids, and to readvertise for other bids when any such bids are not,

in its judgment, satisfactory. The letting of the bid shall not be

complete until the contract is duly executed, and the bonds

approved.