Parks on the Air ® (POTA) is a program for international portable amateur radio operations that promotes emergency awareness and communications from national/federal and state/provincial level parks.  It's a lot of fun and whenever I have a few minutes during the day I scroll through the bands hunt a few parks.  I love talking to folks who are out enjoying the great outdoors in our glorious parks.  It's an international program and I ocasioanlly reach a  DX park.  You can find more info here -> https://parksontheair.com  
You may also sign up for the  program at the app, here -> https://pota.app/