"Bridgestone Americas Tube Business (BATB), a division of Bridgestone Americas Tire Operations, LLC, is based in Russellville, Arkansas. For over 47 years, BATB has been committed to manufacturing quality synthetic and natural rubber inner tubes for both on and off the highway usage. We offer the most comprehensive product line in the industry ranging from Forestry tubes to Lawn and Garden tubes. In addition to inner tubes, BATB produces bladder stock for other Bridgestone plants to use in the production of tires. Today, BATB is the only inner tube manufacturer in the U.S. and Canada."
So, you need to find yourself a Firestone/Bridgestone dealer locally.