Depends a lot by agency and specific role. Many park rangers are mainly focused on conservation, maintenance work or public education. There are also law enforcement rangers who are explicitly cops. The forest service law enforcement guys I used to interact with definitely seemed like some of the most tolerable cops I've ever interacted with (because they are mainly dedicated to protecting a public resource rather than private property). That being said, they are still cops who will be on the other side of the line when the chips are down.

Also, this nuance doesn't apply to urban national parks law enforcement rangers. Some of the worst cops around, taking continuous harassment of homeless people to the next level