I would have to say California. You had the gold rush, Indian troubles, lost mines, cowboys (the Californios were considered the best of the best) and your shoot outs, etc. No less an authority than Louis L'Amour said that Los Angeles, in it's day, was the most violent city of the old west, out ranking both Dodge city and Tombstone for it's level of violence including gun fights, shootings, stabbings, etc. A good book on the subject recently written is "Gold Dust and Gunsmoke: Tales of Gold Rush Outlaws, Gunfighters, Lawmen, and Vigilantes" by John Boessenecker. Very interesting reading. I think that most people would be surprised to find out about some of the things that happened from the bull vs bear fights (an early form of Sunday entertainment) to the mass murders, to the organized crime, to the efforts of early lawmen who fought them. (Bet you never heard of the California Rangers! But they existed!) California at one time or other had it all happen there.