When any responsible protective agency or agencies composed of timber owners other than the state agrees to undertake systematic forest protection in cooperation with the state and such cooperation appears to the department to be more advantageous to the state than the state-provided forest fire services, the department may designate suitable areas to be official cooperative districts and substitute cooperative services for the state-provided services. The department may cooperate in the compensation for expenses of preventing and controlling fire in cooperative districts to the extent it considers equitable on behalf of the state.