I can almost bet they are chinese made tires. I had a tire disintegrate on my 2011 Rockwood, I replaced all my tires with USA made Goodyear Marathon tires. The Marathon tires are both made in the US and China, insist on a set made in the US with a date code that is less than a year old.
2013 Prime Time 230 FBS
Days camped in 2013: April to November
Days camped in 2014...about 40
Days camped in 2015...more than 2014!!