Some of the world's tallest, widest trees are back on view at Yosemite National Park in the newly restored Mariposa Grove. The area is home to 500 giant sequoias, which can live to be more than 3,000 years old.

The $40 million restoration project was three years in the making. It included rehabbing faltering wetland habitat, replacing pavement trails with natural surfaces, and removing all commercial activity from the grove.

"As the largest protection, restoration and improvement project in park history, this milestone reflects the unbridled passion so many people have to care for Yosemite so that future generations can experience majestic places like Mariposa Grove," Yosemite National Park Superintendent Michael Reynolds said in a statement.

"These trees sowed the seeds of the national park idea in the 1800s, and because of this incredible project it will remain one of the world's most significant natural and cultural resources."

The National Park Service and Yosemite Conservancy each provided $20 million to fund the project. The grove has been closed to the public since July 2015 when restoration started.

Towering through history

Grizzly Giant sequoia in Yosemite Mariposa Grove The famous Grizzly Giant stands tall in Mariposa Grove. (Photo: Allie_Caulfield/flickr)

In 1864, President Abraham Lincoln signed legislation protecting the Mariposa Grove and Yosemite Valley for "public use, resort, and recreation." The Yosemite Grant Act was the nation's first legislation focused on preserving public lands.

The towering sequoias (Sequoiadendron giganteum) live in three areas of Yosemite including the smaller — and less visited — Tuolumne and Merced groves.

Yosemite's famous Grizzly Giant in Mariposa Grove is estimated to be 1,800 years old. Another sequoia, the General Sherman is the world's largest tree measured by volume. Found in Sequoia National Park, the tree stands 275 feet (83 meters) tall, and is over 36 feet (11 meters) in diameter at the base.

At one point, tunnels were cut into several sequoia trees in Yosemite so cars could drive through them as tourist attractions. The most famous was the Wawona Tree, which was cut in 1881. According to the National Park Service, the Wawona Tree was 234 feet high (71.3 meters) and 26 feet in diameter (7.9 meters) at the base. It stood for 88 summers before it fell during the winter of 1968-69, likely due to heavy snow, wet soil, and the continued weakening effect of the tunnel. When it fell, the tree was about 2,100 years old.

New rules for the grove

There's no driving through trees anymore in Mariposa Grove. In fact, there's no driving or parking in the grove at all. Instead, shuttle buses take visitors to a new arrival area, giving visitors a taste of the 4-acre habitat restoration project. In which what was once a parking area, asphalt and concrete trails have been replaced by natural surfaces, and boardwalk paths cross over sensitive wetlands. Visitors can now stroll among these aging giants and their newly restored habitat. (You can see how some of the improvements will change the visitor experience in the video above.)

"The grove restoration occurred because tens of thousands of people all invested in protecting a unique natural phenomenon," said Yosemite Conservancy President Frank Dean. "Trails are supposed to take visitors someplace magical. Today, a walk in the grove has been transformed into a more beautiful and peaceful experience with the focus squarely on the trees."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

Project restores majesty of Yosemite sequoias
A 3-year, $40 million project restores Mariposa Grove and the giant sequoias at Yosemite.