What cowboy wore a mask?

This is a bit of a trick question! There isn't one specific cowboy who is famous for wearing a mask. However, you might be thinking about:

* The Lone Ranger: This iconic masked hero is often depicted as a cowboy, although he's more of a lawman than a rancher.

* The Phantom of the Opera: This classic character, although not technically a cowboy, is often associated with the Wild West due to the popular Andrew Lloyd Webber musical set in the 1880s.

Let me know if you were thinking of something else!