Yosemite National Park on Monday marked 150 years since President Abraham Lincoln signed an act protecting the park for generations of visitors. The celebration included a groundbreaking to launch a project restoring the Mariposa Grove, which comprises 500 mature giant sequoia trees that are among the oldest living organisms in the world. National Park Service Director Jon Jarvis said the anniversary should be a reminder of the ancient treasures within the park. Clockwise from top: tourists walk past the Fallen Monarch in Mariposa Grove; Lt. Gov. Gavin Newsom wears the hat of Park Service public information officer Scott Gediman; California State Park ranger Emily Peterson and Miles Standish, in character as pioneer Galen Clark, stand by during the anniversary ceremony; and families hike to see the grandeur of the Grizzly Giant, the largest giant sequoia in Mariposa Grove.