Thunderclouds, Garnet Lake — by Peter Essick from the series “Ansel Adams Wilderness” By Alexandra Mathews From the geysers of Yellowstone to the palms of the Everglades, national parks have played a crucial role in preserving America’s natural history. August 25, 2016 marks the 100th birthday of the National Park Service (NPS). This anniversary reflects significant achievement and growth in the NPS. Here are five things to know about national parks and the NPS as its centennial approaches:

1. In 1872, Ulysses S. Grant signed the country's, and likely world's, first national park, Yellowstone in Wyoming, into law. Forming a national park was a fairly revolutionary idea, and Grant wanted to ensure preservation of Yellowstone and all of America’s other natural treasures. Pinnacles National Park in California, the newest addition to the National Park System, was signed into law in 2013 by President Barack Obama.
   
   
   
   
   
    
   A clear view of Denali, the highest peak in North America, on May 14, 2014 in Denali National Park, Alaska. Photo by Lance King/Getty Images.


2. The NPS, a bureau of the U.S. Department of the In terior, was not created until 1916, decades after America's first national park was formed in 1872. After the formation of Yellowstone, Yosemite, the Grand Canyon and 32 other parks, President Woodrow Wilson signed the Organic Act into law on August 25, 1916, officially forming the NPS. In their early years, Yellowstone and the first few parks were neglected and exploited. By 1918, reform efforts were underway and new leadership managed to prevent the neglect of the parks and conserve them for future generations.


3. At over 84 million acres with 412 sites, the National Park System offers a diverse range of parks, including 25 battlefields or military parks and 10 seashores. The sites also include four parkways, 81 national monuments, two reserves and 128 historical sites. These include the sites of many historically significant events, such as the Harriet Tubman Underground Railroad National Historic Park in Maryland and the Brown V. Board of Education National Historic Site in Kansas. The sizes of national parks also vary greatly. The largest park, Wrangell-St. Elias National Park and Preserve in Alaska, is larger than Switzerland at 13.2 million acres, while the smallest, Thaddeus Kosciuszko National Memorial in Philadelphia is 0.02 acres.
   
   
   
   
   
    
   The sun sets at Grand Canyon National Park in northern Arizona, April 14, 2015. Picture taken April 14. Photo by Jim Urquhart/Reuters


4. The National Park System holds the lowest point in North America, the largest living tree, an active volcano and many other unique natural wonders. Death Valley National Park , in California and Nevada is the hottest and lowest point in North America at 282 feet below sea level. With more than 400 miles explored, Mammoth Cave National Park in Kentucky holds the longest cave system in the world. The largest and one of the oldest living trees in the world, known as General Sherman, resides in Sequoia National Park at an estimated age of 2,000 years and volume of 52,500 cubic feet.


5. “ Find Your Park ”, co-chaired by First Lady Michelle Obama and former First Lady Laura Bush, is a new NPS campaign targeted towards young Americans. The social media initiative formed in March, 2015, and aims to increase interest in national parks. The campaign compiles various stories of national parks through #FindYourPark on Twitter and Instagram . It is publicized through many well-known figures, including educator Bill Nye and actress Bella Thorne.

Amid waving prairie grasses in the middle of the Great Plains winds this river https://t.co/CJ0qaI24dJ #FindYourPark pic.twitter.com/aerFSdrWiz

— NationalParkService (@NatlParkService) July 6, 2016

Watch two friends explore the national parks as they take #FindYourPark to the next level with this video: Pair Tackles 59 National Parks in 59 weeks