Are you looking for the top U.S. national parks, ranked from stunning to must-visit? Read on for a list of the best U.S. national parks you can visit this season.

As summer tourism season heats up, the U.S. National Parks system typically readies for its biggest crowds of the year, but some parks that usually see large numbers of Canadian visitors are starting to notice a worrying trend that could have a major impact this year.

Earth Day also falls during National Park Week. Celebrated for 55 years, one billion people in 193 countries host events and celebrations of the planet, its resources and our commitment to protect it. Many of our national parks will have special Earth Day demonstrations of earth science or discussions of the latest environmental concerns.