FRESNO, Calif. -- A wildfire burning inside Yosemite National Park has forced evacuations.Approximately 100 hikers were evacuated from the top of Half Dome, Little Yosemite Valley, and surrounding trails, via helicopter.Crews are looking into whether this is tied to the Meadow Fire that was sparked by lightning back on July 20, park spokeswoman Kari Cobb said. For weeks, that fire stayed at about 19 acres, and crews were just monitoring and controlling it. But around noon Saturday, they believe the wind may have fanned the flames and started a new spot fire that has grown to approximately 700 acres.Throughout the afternoon, 7 helicopters, an airplane, and ground crews worked to extinguish the fire. At this point, there is no word on containment.The area, at 7,000 feet in elevation, features rugged terrain. Ground access requires a several mile hike to the area affected by the fire. Yosemite National Park firefighters are working with fire crews from Cal Fire, Sequoia-Kings Canyon National Parks, Mariposa County Fire, California Highway Patrol, and U.S. Forest Service. There are over 100 firefighters dedicated to the fire, with more resources en route.Yosemite National Park remains open and all facilities within Yosemite Valley. Trails near the Half Dome area, the Little Yosemite Valley area (a backcountry camping area near Half Dome), Merced Lake and Sunrise High Sierra Camps, Clouds Rest, and Echo Valley remain closed due to fire activity. All roads leading into Yosemite remain open.Visitors are being asked to leave the Merced Lake, Sunrise and Vogelsang High Sierra Camps to allow firefighters to work.People who have permits to hike Half Dome in the next few days can call (209) 372-0826 for an update.Visitors can also call the fire information line before heading into the park. That number is (209) 372-0327.There are no reported injuries or structures affected by the wildfire. The cause of the fire is still under investigation.