The Texas Trailhands, though I've not seen them in several years are still winning recognitions from fans of western music. They have a website.

Red Stegall - I did not see mention of him but he deserves a listen.

Gillette Brothers - Ditto what Dale said, and you really should see them live if you get the chance. Same goes for the Texas Trailhands. The Gillettes don't blow you away with theatrics but their music is carefully chosen and well done and put into historical perspective.

Bob Campbell - has written some great western songs including one about Arbuckle Coffee and other artists are doing many of his songs.