A variety of projects, from picking up trash to planting trees, are scheduled Saturday for the 20th anniversary of National Public Lands Day.
Yosemite National Park is waiving park entrance fees for all visitors Saturday.
"The idea is for people to go out and enjoy their public lands," said park spokesman Scott Gediman.
The park's 10th annual Yosemite Facelift started Wednesday and will last through Sunday.
That event - sponsored by the Yosemite Climbing Association in cooperation with the National Park Service - aims to clean up trash throughout the park following the busy summer season.
Gediman was one of hundreds of people who helped pick up garbage Wednesday afternoon. Among his findings: water bottles, soda cans, toilet paper, a broken Smokey Bear frisbee and a bottle of salad dressing.
"It's a wonderful volunteer project," he said.
Last year, more than 1,200 volunteers worked 9,390 hours to collect more than 20,000 pounds of trash. More than 95 percent of the trash collected was recycled.
Those wanting to help this year can sign up at the Yosemite Valley Visitor Center from 8 a.m. to 4 p.m. today through Sunday. Another station at the Tuolumne Meadows Wilderness Center will be open 8 a.m. to 3 p.m. Friday through Sunday. There will be a third station in Wawona at the Mariposa Grove lower parking lot from 9 a.m. to noon Saturday.
Crew leaders will be at the stations to organize work groups and hand out trash bags, gloves and litter sticks.
A volunteer awards ceremony will be held at 4 p.m. Saturday in front of the Yosemite Valley Visitor Center.
Also on Saturday, the Stanislaus National Forest is partnering with the Bureau of Land Management on a project installing interpretive kiosks and signs along the West Side Trail in Tuolumne. The trailhead can be found at the intersection of Buchanan and Mira Monte roads.
Work projects will take place at area reservoirs as well.
Volunteers at New Melones Reservoir, which will waive all day-use fees Saturday, will help with invasive plant removal and planting native vegetation from 9 a.m. to 2 p.m. They may also visit the reservoir's new greenhouse, where some of the native plants they will be planting were grown.
On-site registration and check-in will begin at 8:30 a.m. at the New Melones Visitor Center, 6850 Studhorse Flat Road, north of Sonora.
Projects at New Hogan Reservoir include tree planting, restoration, painting and shoreline cleanup. Volunteers will receive a free barbecue lunch.
Last year, about 200 volunteers planted about 60 trees and picked up hundreds of bags of trash.
Saturday's event is scheduled from 7:30 a.m. to 1 p.m. at the park's headquarters, 2713 Hogan Dam Road in Valley Springs.
"We definitely look forward to getting a good turnout of volunteers," said park ranger Alicia Unsinn.
Volunteers at New Melones and New Hogan will receive a "fee-free day" voucher good for admission to any federally-managed public land.
Those unable to lend a hand Saturday can check out area museums as part of the Smithsonian's "Museum Day Live!" event.
The Angels Camp Museum, 753 South Main Street, will offer free admission from 10 a.m. to 4 p.m. Saturday to those who download a Museum Day ticket at www.smithsonianmag.com/museumday.
The Tuolumne County Museum, housed in the old county jail, will take part in Museum Day from 11 a.m. to 2 p.m. The museum, at 158 W. Bradford Ave. in Sonora, will offer new exhibits, book signings and tours led by docents dressed in period costumes.
"So many people don't even know we're here, and they're locals," said museum coordinator Audie Buckler.