Residents of Tombstone included Kid Colt, Phantom Rider, Rawhide Kid and Two-Gun Kid. Black Rider, Kid Cassidy and Reno Jones possibly also lived there. Kang the Conqueror ruled Tombstone making it his home for a time.
Visitors to Tombstone include various teams of Avengers during time travel adventures. The first team which visited Tombstone consisted of Hawkeye, Moondragon and Thor. This team visited during Kang's rule and allied with the western heroes to overthrow Kang which resulted in Two-Gun Kid joining the Avengers as an official member and journeying to present day time along with them.
A second team of Avengers consisting of Hawkeye, Iron Man, Mockingbird, Tigra and Wonder Man visited Tombstone some time after Kang's rule where they met Two-Gun Kid (who had since returned to his time) and his fellow gun-slingers. Although most of the team didn't remain there for long, Mockingbird was stranded in the time period when she was kidnapped by the Phantom Rider. Drugging her into compliance, Phantom Rider made Mockingbird into his "wife" and was hunted by the only available Avenger to save Mockingbird: Two-Gun Kid. Eventually shrugging off the effects of Phantom Rider's drugs, Mockingbird freed herself and fought the man who had abused her and watched happily as he fell of a cliff. The rest of the Avengers, now joined by Firebird, Hank Pym and Moon Knight, returned to bring Mockingbird back to the present day.
A third team of Avengers consisting of Hawkeye, Songbird and Yellowjacket also visited Tombstone, again during Kang's rule. Despite their desire to intervene and stop Kang, they were forced to avoid confronting Kang or helping as they knew Kang's rule would eventually be stopped by an early iteration of the Avengers sometime later. The team fought against Phantoms disguised as Black Rider, Kid Cassidy and Reno Jones.