Yosemite National Park is celebrating the 150th anniversary of President Abraham Lincoln's signing of the Yosemite Grant Act, which protected Yosemite Valley and Mariposa Grove.
California Lt. Gov. Gavin Newsom and U.S. Reps. Tom McClintock and Jim Costa are among those expected to be on hand for Monday's commemoration at the park.
The event will also include a groundbreaking ceremony for a project to restore Mariposa Grove, which consists of 500 mature giant sequoia trees that are among the oldest living organisms in the world.
The project calls for removing parking and other asphalt in the grove to help the trees reproduce.
Lincoln signed the Yosemite Grant Act in the midst of the Civil War. It is viewed by many as the birth of the country's national park system.