The Canyon of Adventure (1928)

Set in the days before California became a state, Steven Bancroft, a young officer in the U. S. Calvary, is given the assignment of ensuring that dirty-work by agents of Spain, Mexico or Russian aren't going to keep statehood-for-California from becoming a reality. Bancroft uses his guns to settle any debates regarding international laws. His horse, Tarzan, also comes in handy.