Watch! Viggo Mortensen Celebrates 100 Years of National Parks"Captain Fantastic" star Viggo Mortensen joins with the Sierra Club to celebrate the National Park Service Centennial and looks forward to the next 100 years of conservation and nearby nature. Help Celebrate Our National ParksLooking for a National Park Service 100th anniversary T-shirt, national park notecards, a classic Sierra Club stainless steel camping cup, or other gear? We've got it! Sierra Club Outings -- Book Your Trip Today!2016 trips are here. We've got 300+ ideas for you. Support Clean Energy, Get 4 Free LEDsSign up with Arcadia Power today and they'll send the Sierra Club a donation -- plus you'll receive 4 free LEDs.