UPDATE: The U.S. Forest Service says they have determined the cause of the Ferguson Fire that started in July.

They said the cause was vehicle-related and investigators believe super-heated pieces of catalytic converter ignited dry, roadside vegetation.

The Ferguson Fire burned a total of 96,901 acres of the Sierra National Forest, Stanislaus National Forest and Yosemite National Park.

Officials are asking anyone with any information on a suspect vehicle to contact the Sierra National Forest at (559) 297-0706.

(The U.S. Forest Service contributed to this report).

The Ferguson Fire that raged in California for over a month is now 100% contained burning a total of 96,901 acres.

Officials say that while this is a huge milestone, that there is still much more work to be done. Firefighters will continue to mop up and repair firelines. They are also going to continue to remove hazard trees along the roads. 881 personnel helped fight the flames of this fire.

The cause of the fire is still under investigation.

To see detailed road closures, click here.

Most of Yosemite National Park is set to reopen after a 20-day closure that cost the surrounding communities an estimated $50 million in lost tourism dollars.

Yosemite Valley, which includes most of the park's major attractions, is set to reopen Tuesday but hotels and other businesses say it will likely be weeks before bookings return to normal levels.

The nearly three-week closure was the result of the nearby massive Ferguson Fire that has burned 96,824 acres and killed two firefighters since it started July 13.

Though the blaze didn't reach the heart of the park, it burned in remote areas, making roads inaccessible and polluting the area with smoke.

Visitors can access Yosemite Valley from the El Portal Road (Highway 140), the Big Oak Flat Road (Highway 120), or the Tioga Road (Highway 120).

The Mariposa Grove of Giant Sequoias will reopen to the public on Monday, August 13th, at 9:00 a.m. Visitors can access the Mariposa Grove via the South Entrance (Highway 41) and park in the newly constructed parking area. The free shuttle buses to the Mariposa Grove will begin at 9:00 am. and take visitors to the newly restored Mariposa Grove of Giant Sequoias. The Mariposa Grove reopened to visitors on June 14th, after a 3 year restoration project conducted in partnership with Yosemite Conservancy. Visitors will be able to travel to the Wawona area via the South Entrance (Highway 41). However, there is no access to Yosemite Valley via Highway 41.

The Glacier Point Road remains closed and is expected to open when the Wawona Road (Highway 41) reopens. The Hetch Hetchy Area remains closed due to smoke impacts but is expected to reopen soon.

The fire is currently 87% contained with full containment expected Wednesday. 

The cause of the fire remains unknown.

(National Park Service contributed to this report.)

The U.S. Forest Service says a mandatory evacuation is issued for Yosemite Valley due to the growing Ferguson Fire. 

The evacuation is because of multiple hazards along El Portal Road, Big Oak Flat Road, and Wawona Road, as well as power outages in Yosemite Valley.

El Portal Road (extension of Highway 140 within the park) and Big Oak Flat Road west of Crane Flat may be closed for an extended period of time due to fire activity, hazard trees, and firefighters working on the roads.

Access to Yosemite Valley is closed through Sunday due to fire operations. This includes El Portal Road (Highway 140 inside the park), Wawona Road (Highway 41 inside the park), and Big Oak Flat Road (Highway 120, inside the park between the Big Oak Flat Entrance Station and Yosemite Valley).

Currently the only public access into Yosemite National Park is via Tioga Pass from Highway 120 east via U.S. 395 from Lee Vining. The Tioga Road remains open to Crane Flat. 

Authorities stress as of now, Yosemite Valley itself is not threatened. 

The fire has burned 77,207 acres and remains 41% contained. 

One structure has been destroyed. 

Yosemite National Park announces Yosemite Valley, Wawona Road, the Mariposa Grove of Giant Sequoias, the Merced Grove of Giant Sequoias, Hetch Hetchy, and other areas will remain closed to all visitors through Sunday, August 5, due to continued unhealthy smoke impacts and ongoing firefighting operations. 

Highway 140 is closed from 1.9 miles east of Midpines to the Cedar Lodge area.

Two firefighters died while battling the Ferguson Fire. Brian Hughes died from a falling tree July 29. Hughes, originally from Hawaii, had been with California's Arrowhead Interagency Hotshots for four years and reached the rank of captain. A memorial service is scheduled Saturday at Fresno Convention Center. Hughes also lived in Squaw Valley.

Braden Varney was killed when a bulldozer he was operating overturned. At least nine other firefighters have been injured since the blaze broke out July 13.