Simplify the following text for a Grade 13 native English-speaking person.
Original: He traveled in northern Mexico and the American Southwest , including Texas and Oklahoma , earning a living as a buffalo hunter , cowboy , and prospector , and he continued working as a scout while tracking Indians in the Cheyenne War .
Simplified: He traveled in northern Mexico and the American Southwest , including Texas and Oklahoma , earning a living as a buffalo hunter , cowboy , and prospector , and he continued working as a scout .