Colleges
A college degree and/or the right combination of education and experience in park recreation and management will possibly get you in on the ground level of this profession. Job openings are few and competition is fierce, so college credits in forestry, geology, botany, conservation, wildlife management, and other relevant subjects will go a long way in equipping you for a career that offers a multitude of possibilities.
http://rangerschool.esf.edu/rangerschool/ranger.htm