Ranger Marty tells us a little about becoming a ranger:
Job qualifications for Ranger vary by agency - whether it be National Parks, US Forest Service, or each individual state's Park service and Forest service. For my agency (Tennessee State Parks), Rangers have to complete at least a Bachelors Degree at an accredited 4-year college. Acceptable majors would include forestry, wildlife management, ecology, history (for historic parks), or related fields. We also look at experience - folks who wish to become Rangers should have shown their interest by their volunteer work, their hobbies, and their previous paid employment. Rangers usually begin as seasonal (summer) employees while they are still in college.
For more detailed information, check out this website:
Many thanks, Marty, for the information!