June 30th, 1864, 155 years ago today, the day President Abraham Lincoln signed the Yosemite Valley Grant Act.
The act gave the state of California ownership of the valley "upon the express conditions that the premises shall be held for public use, resort, and recreation."
But Yosemite's protected status failed to fully protect its wonders in the view of conservationist John Muir.
He complained of intrusive tourists and fumed over commercial sheep grazing on Yosemite's meadows. "Hoofed locusts", he called them.
Thanks in large part to his lobbying, Yosemite became a national park in 1890 and, in 1903, Muir famously led President Theodore Roosevelt on a tour.
Many millions of other visitors have followed in their footsteps.
At nearly 1,200 square miles, Yosemite's natural wonders include towering El Capitan, rising nearly 3,600 feet over the valley floor, roughly the height of two-and-a-half Empire State Buildings.
Even taller is Half Dome. At just over 4,700 feet it's almost a full mile tall.
And don't forget Yosemite Falls, a series of three cascades popular with hikers. Not that Yosemite's must-see attractions can always be seen.
Last summer's Ferguson Fire filled Yosemite Valley with smoke, forcing the park to close for almost two weeks.
No similar fire this year so far, but the Park did make a "Fire Season" declaration earlier this month, "due to hotter and drier weather conditions."