We’re smack dab in the middle of National Park Week (April 16-24), which means this weekend, all national park units are waving their admission fee. Head to Shenandoah National Park and hike the park’s trails gratis as the trees begin to bud. The Great Smoky Mountains National Park one of the few park units that’s always free, but this week is an ideal time to visit as the park’s wildlife become more active with the warmer weather. Check out the elk, and maybe hug a park ranger. If you’ve got kids, this saturday is Junior Ranger Day with special programs about history and nature.

Check out specific activities for the weekend here.