Group Cabin Camping. Group Cabin Camping - Prince William Forest Park (U.S. National Park Service) These cabin camps are rented to large groups of people. For in-depth information on the facilities in each of the five historic camps, click on the links below. You may call the cabin camp office at 703-221-4706 ext. 401. You may also email us your questions! To rent a cabin for just you or your family, see our webpage for individual cabins. Please be aware that cabin campers are obligated to pay the park entrance fee or possess a valid National Park pass.