There's not an awful lot of genuine cowboy songs or singers on record, probably because the golden age of cattle punching was over by the time the record industry started recording such stuff. However, one compilation well worth checking out is Back in the Saddle Again. New World. NW 314/315-2.

Also Cowboy Songs, Ballads & Cattle Calls from Texas. Library of Congress. AAFS L28. I have this as an LP, although it was reissued by Rounder, in the days before Rounder got sold and asset stripped. Whatever, it has some wonderful stuff on it, and it would be well worth searching out.