Happy 143rd birthday, Yellowstone National Park! On this day in 1872, Yellowstone became the first national park – starting a worldwide movement to protect special places. Today, millions visit Yellowstone to discover the park’s geysers and mud pots, forests and lakes, and historic cabins and prehistoric sites – not to mention it’s stunning waterfalls. Pictured here is a rainbow at Lower Falls on the park’s Uncle Tom trail. Photo by Kallem Phillips (www.sharetheexperience.org).