Ark. Code Ann. § 13-2-102

All county public libraries created under the authority of § 13-2-401 et seq. and all city public libraries created under the authority of § 13-2-501 et seq. which have entered into interlocal cooperation agreements or any other formal or informal or contractual arrangements to form a joint city-county library, a regional library or library system, or any other form of multiple-jurisdiction library system which are not in written format shall within one (1) year formalize and renew in writing all such agreements and contractual arrangements among the libraries.