This site has a lot of information on Nat'l and State park rangers.
I think the question to ask is when preserving and protecting our natural resources, which path do you want to take? Do you want to educate people, perhaps doing informative tours, or even skits, at national parks; do you want to catch people breaking the laws, which would be a law enforcement role; do you want to work on changing public policy, such as the Endangered Species Act, or bringing violators to justice, which would be in the legal field, or do research to support all these other roles, such as marine biologist?
Protecting our resources truly is a team effort! While you mention that you like being in nature, you don't mention anything about people. Where there are parks, there are people. Too many of them! Many park rangers are almost constantly around people, rather than being out in nature. I encourage you to research the different roles park rangers fulfill, and, to also look at state positions. Additionally, since there are many summer or seasonal positions available within the parks, try to get one of these so you can get some first-hand experience!
In addition to "park rangers," some states have other positions. For example, in Texas, we also have "Game Wardens," a highly sought after law enforcement position.
I wish you the best in your career, wherever it may take you!