Okla. Stat. tit. 19, § 19-168: Volunteer - Protection of sovereign immunity - Travel and

training expenses.

Persons who are not county employees, but who are performing

substantial and necessary services to the county on a voluntary

basis without compensation which have been directed and approved by

a county officer, shall enjoy the protection of sovereign immunity

of the state to the same extent as a paid employee. Such persons

may be reimbursed for expenses incurred during authorized official

travel pursuant to the State Travel Reimbursement Act, Section 500.1

et seq. of Title 74 of the Oklahoma Statutes, or for training

expenses, provided it is indicated on the claim the person is not a

county employee, a description of services performed is entered, and

the officer, by his approval of the claim, certifies such services

were substantial, necessary and germane to the duties and functions

of the county office.