Okla. Stat. tit. 12 § 1192
That it shall be lawful for any creditor of any person, firm or corporation in this state, to whom the state or any county, city, town, school board, board of education or any municipal subdivision of the state is indebted, to cause a garnishment to issue to, and to garnishee sums, wages or other sums due such creditor of the state or such municipality to the same extent and in like manner as if such creditor of the state or such municipality was a creditor of a private individual, firm or corporation; provided, however, that such officer or employee of said state, county or municipality shall be entitled to the exemptions as to amount of such wages, salary, fund or compensation due thereto, as is exempt from attachment, execution or garnishment in favor of officers or employees of private individuals or corporations.
Okla. Stat. tit. 12, § 1192