Here is an easy way to determine the location/manufacturer of any tire. The first 2 characters after the "DOT" on the tire is what to lookup against. This is especially useful for determining the manufacturer of store brand/generic tires. FOr example, the Yokohama tires on my vehicle have a code of DOT CC****. The CC matches up to Yohahama tire is Salem, VA
http://www.tireaccidents.com/tire_plant_codes.htm