The parties to this case are the plaintiff Sierra Club which is an environmental group and the defendants composed of Mr. Lujan who is the Secretary of Interior and TW Recreational Services (The Sierra Club v. Lujan, et al.). This case involved the north rim of Grand Canyon where there was a planned construction of hotel and restaurant complex (The Sierra Club v. Lujan, et al.). In this case, the National Park Service (NPS) planned to build a new hotel complex on the North Rim and hence, entered into a contract in 1984 with a concessionaire, TW Recreational Services, Inc. (TW) (The Sierra Club v. Lujan, et al.). TW would be constructing a new hotel, which would include a restaurant, employee dining facility and other improvements (The Sierra Club v. Lujan, et al.). These improvements were, however, subject to the limitations and provisions of the National Environmental Policy Act (NEPA) and the National Historic Preservation Act of 1966 as acknowledged in the contract. They further allege that snowmobiling and trail grooming caused air and noise pollution, threaten wildlife and endangered species, and create health threats to visitors and park employees (The Fund for Animals v. Norton). Defendants, on the other hand, argue that their own Management Policies are not binding on them (The Fund for Animals v. Norton). The NPS also posits that the use of guided group tours will mitigate snowmobiler interaction with wildlife and that limiting entries to 950 snowmobiles per day will greatly reduce the negative impacts of snowmobiles (The Fund for Animals v. Norton).