1. The Trigger Twins, Walt and Wayne Trigger. Walt is the heroic local sheriff, while Wayne is apparently a meek and mild shopkeeper. But unknown to others, Wayne is secretly the hero and Walt simply a goof-prone lawman who relies on his brother to dress up as him and capture the bad guys. In an amusing twist on the Lois/Clark/Superman theme, Linda, Wayne's assistant, notices how often her boss disappears from view whenever there's trouble, but she attributes it not to him sneaking off to dress up as the sheriff, but as real cowardice.
2. Pow-Wow Smith, Indian lawman. A Sioux deputy sheriff who appeared for several years as a backup in Detective Comics and was often cover-featured on Western Comics:
3. The Nighthawk:
The Nighthawk was a "fix-it" man, who while roaming from town to town repairing items also solved crimes in a secret identity as a masked man with a hawk emblem on his chest.
4. The Wyoming Kid was a wandering cowboy who fought cattle rustlers and other western crooks.
5. Strong Bow was a 1400s Native American who traveled around North America, righting wrongs and fighting foes.
Kudos to Michael Sensei, who got them all!