A little over 100 years ago, President Woodrow Wilson signed the National Park Service into law, ensuring that the country’s most remarkable natural landscapes would be preserved for future generations. Today, national parks are more popular than ever, with millions of visitors passing through the system’s 400-odd properties each year. But even if you’re working to check every national park off your bucket list, you may be unfamiliar with some of these facts. For instance, did you know that Dolly Parton is an official ambassador to Great Smoky Mountains National Park? Or that Yosemite campaigned to host the Winter Olympics in 1932?

That’s just some of the trivia John Green shares in this latest video from Mental Floss on YouTube. You can check out all 31 facts above, then subscribe to our channel if you're still hungry for more brain food.