Aircraft shall only be stored or parked at places designated by the airport manager and such storage or parking shall be at the sole risk of the owner or operator of the aircraft, and without any responsibility of the Sierraville-Dearwater Airport, county, or any of its officers or employees, for any loss of, or damage to, the aircraft while so stored or parked. The owner or operator of the aircraft shall be responsible for the tying-down and securing of his aircraft. He shall likewise be responsible for any liability arising from or caused by his aircraft or his activities.