The U.S. National Park Service will waive entrance fees at more than 100 national parks during three special weekends this summer. Designed to promote tourism and help budget strapped families at the same time, these weekends are scheduled for June 20 & 21, July 18 & 19 and August 15 & 16. If you are thinking of packing up the car and heading out, be sure to stop by the library and& check out one of our many National Park Guidebooks.