THE PONY RIDER BOYS IN THE ROCKIES;
Or, The Secret of the Lost Claim.
THE PONY RIDER BOYS IN TEXAS;
Or, The Veiled Riddle of the Plains.
THE PONY RIDER BOYS IN MONTANA;
Or, The Mystery of the Old Custer Trail.
THE PONY RIDER BOYS IN THE OZARKS;
Or, The Secret of Ruby Mountain.
THE PONY RIDER BOYS IN THE ALKALI;
Or, Finding a Key to the Desert Maze.
THE PONY RIDER BOYS IN NEW MEXICO;
Or, The End of the Silver Trail.
THE PONY RIDER BOYS IN THE GRAND CANYON;
Or, The Mystery of Bright Angel Gulch.