What's Aaron Watson wearing on the cover of The Road and the Rodeo?

Hello All, My boyfriend gave me the task of trying to figure out what brand name/designer the shirt Aaron Watson is wearing on his new album cover is. He really likes it so we want to try and see if we can find it either at a store or online, but I can't seem to find any info on it. Any ideas? Has anyone seen or does anyone own this shirt? Thanks!