Okla. Stat. tit. 74, § 74-1255: Travel expenses - Per diem

A sending agency in this State may, in accordance with the

travel regulations of such agency, pay the travel expenses of

employees assigned to a receiving agency on either a detail or leave

basis, but shall not pay the travel expenses of such employees

incurred in connection with their work assignments at the receiving

agency. During the period of assignment, the sending agency may pay

a per diem allowance to the employee on assignment or detail.