A wildfire in Yosemite National Park is threatening some of the oldest and most massive trees on the planet. The iconic Mariposa Grove of Giant Sequoias, visited by a million people every year, is now closed as firefighters battle the Washburn Fire that threatens to engulf it. Hotshot crews – personnel specially trained to fight wildland fires – battle the powerful fire, which began July 7 and has burned more than 2,300 acres. It doubled in size during a single day and threatens the 248-acre Mariposa Grove, home to more than 500 sequoias, some 3,000 years old or older. About 545 people were fighting the fire as of Monday, the National Park Service said. To read more about the wildfires and efforts to save the sequoias, click the link in our bio.