A seven-day pass to Yellowstone and Grand Teton National Parks is normally $25 for a private, noncommercial vehicle. The entrance fee waiver does not include other fees such as those charged for camping, reservations, tours and use of concessions services.
All park roads, lodging, and stores are open for the season, as are most of Yellowstone’s campgrounds. You can see a full list of 2011 opening and closing dates here.
Additional fee free days in 2011 are National Public Lands Day on Saturday, September 24, and the Veterans Day weekend, November 11-13.