I LOVE PBS - The National Parks: America's Best Idea - a Ken Burns documentary about how the parks came to be. Hours of film of the people involved. John Muir, Teddy Roosevelt, Ansel Adams...

https://www.pbs.org/kenburns/the-national-parks/

The National Parks: America's Best Idea is a six-episode series produced by Ken Burns and Dayton Duncan and written by Dayton Duncan. Filmed over the course of more than six years at some of nature's most spectacular locales – from Acadia to Yosemite, Yellowstone to the Grand Canyon, the Everglades of Florida to the Gates of the Arctic in Alaska.

Great day hikes in Yosemite!

Yosemite Falls Trail

https://www.nps.gov/yose/planyourvisit/yosemitefallstrail.htm

This trail starts near Camp 4 (Sunnyside Campground), along the Valley Loop Trail, and immediately begins its climb, switchback after switchback, through oak woodland.

A steep climb is well rewarded with close-up views of Upper Yosemite Fall and distant views of Half Dome and other Sierra mountain peaks. Along the hike, enjoy a bird's eye view of Yosemite Valley's meadows and the meandering Merced River.

Vernal Fall and Nevada Fall Trails

https://www.nps.gov/yose/planyourvisit/vernalnevadatrail.htm

be aware that the Mist Trail is Slippery When Wet...

Since Trump cut off funding for PBS and NPR it's up to you and me to make sure that this American Treasure Doesn't Vanish...

https://donate.kvie.org/node/619

On a personal note: I don't care if a park is a National Park, State Park, County Park or a City park... 

Some of the most amazing places are in California Parks and I'm thinking of Bumpass Hell in Lassen... And swimming in the Chico Creek in Bidwell Park... Mount Shasta... It appears to me to be haunted... Maybe by Aliens and UFOs... Maybe by Sacred American Indian Spirits... I Don't know but I DID FEEL something at Mount Shasta, something very special... The Hot Springs at Sykes camp in Big Sur... The Redwood Forests... The Pacific Coast Beaches...