National park, as a natural park, has a dual purpose, to promote both protection and enjoyment. The educational activities of the national park can be partly understood as one of the appropriate means to balance its double purposes. This study provides a review of environmental education in the US National Parks according to social transition. Taking historical perspective and case studies, environmental education has played roles in helping the balance between preservation and enjoyment. Since the environmental movement, environmental education goals, particularly understanding the natural processes observable at national parks, has become more a part of the interpretation and education missions of the parks. Also non-governmental and non-profit partners have played important educational-based roles in support of both the National Parks Service and environmental education goals. The two different models also differ in the public’s perception of them. Federal employees are resented in some rural areas in the U.S., but the general population automatically attributes authority, friendliness, and national-interestedness to NPS Rangers. This may in turn limit how strongly such staff could serve as strong advocates for the environment. On the other hand, the non-profit may be seen by some as strongly liberally biased and associated with urban wealth. It is also not as universally recognized as the NPS. It can, however, go far to develop new partnerships and undertake public relations. Non-profits vary greatly in quality, also affecting public perception.