The final plat shall contain a certificate stating that the board of county commissioners accepted, accepted subject to improvement or rejected, on behalf of the public, any land offered for dedication for public use in conformity with the terms of the offer of dedication. Upon full conformance with the county road construction standards, the roads may be accepted for maintenance by the county. Acceptance of offers of dedication on a final plat shall not be effective until the final plat is filed in the office of the county clerk or a resolution of acceptance by the board of county commissioners is filed in such office.