The legislative authority of any county owning property in or outside the limits of any city or town, or anywhere within the county, which is suitable for agricultural fair purposes may by negotiation lease such property for such purposes for a term not to exceed seventy-five years to any nonprofit organization that has demonstrated its qualification to conduct agricultural fairs. Such agricultural fair leases shall not be subject to any requirement of periodic rental adjustments, as provided in RCW 36.34.180, but shall provide for such fixed annual rental as shall appear reasonable, considering the benefit to be derived by the county in the promotion of the fair and in the improvement of the property. The lessee may utilize or rent out such property at times other than during the fair season for nonfair purposes in order to obtain income for fair purposes, and during the fair season may sublease portions of the property for purposes and activities associated with such fair. No sublease shall be valid unless the same shall be approved in writing by the county legislative authority: PROVIDED, That failure of such lessee, except by act of God, war or other emergency beyond its control, to conduct an annual agricultural fair or exhibition, shall cause said lease to be subject to cancellation by the county legislative authority. A county legislative authority entering into an agreement with a nonprofit association to lease property for agricultural fair purposes shall, when requested to do so, file a copy of the lease agreement with the department of agriculture or the state fair commission in order to assure compliance with the provisions of RCW 15.76.165.