In case you haven’t heard yet, the entrance fee for Yellowstone and the Tetons and probably all of the national parks will be waived on three weekends this summer [2010]. The dates are June 5-6, August 14-15, and the one day, September 25, which is National Public Lands Day. The usual combined fee for Yellowstone and the Tetons is $25.00 per vehicle, good for seven days.