Okla. Stat. tit. 11 § 35-204
The sale of any public utility, when authorized by the registered voters, shall be for cash to the highest and best responsible bidder. Each bid shall be accompanied with a certified check payable to the clerk of the municipality for ten percent (10%) of the amount bid. The check shall be cashed by the treasurer of the municipality if the bid to which the check is attached is accepted, and the proceeds thereof shall be held to secure the municipality in damages it might sustain upon the failure of the bidder to pay the amount bid for the utility. The balance of the purchase price shall be payable in cash by the successful bidder upon the execution and delivery of proper legal conveyances and of the property thereby conveyed. The public utility shall not be delivered, nor shall the right to participate in any portion of the income derived therefrom accrue to the purchaser until full payment in cash of the amount of the bid for such utility is made.
Securities in which municipal treasurers are authorized by law to invest sinking funds may be accepted in lieu of cash.
Okla. Stat. tit. 11, § 35-204