(2) On request of the forest road contractor, the county roadmaster shall inspect any completed segment of the contract forest road, and if the county roadmaster determines the work to be in compliance with the contract the county roadmaster shall approve the completion in writing, deliver a copy of the approval to the contractor and file a copy with the county clerk. Except in case of fraud, the approval of the county roadmaster shall be conclusive proof that the work approved is in compliance with the contract.