Williams Supply Outpost Share: VeterinaryAgriculture Services & Supplies Williams Supply Outpost 502 E. Washington Ave. Ava, MO 65608 (417) 683-2422 Hours: Mon - Fri 8:00 - 5:00Sat - 8:00 - 12:00 About About Large animal and pet supply store: carrying pet food, vaccines, veterinary supplies, etc.