The blaze has been dubbed the West Antelope Fire. It is spreading north and east, was 35 percent contained as of Saturday evening. Ground crews and aircraft battled the blaze throughout the day.
Part of the effort was focused on protecting historic structures at the Fielding Garr Ranch, Shaw said, although the ranch was not immediately threatened. Built in 1848 by Fielding Garr, the ranch and is the oldest Anglo-built structure in Utah still on its original foundation, according to a Utah State Parks website.
Antelope Island, a state park that is roughly 15 miles long and 5 miles wide, is the largest of the Great Salt Lake's eight islands. Although it was named for the pronghorn antelope, the island is most-famous for its bison herd 500 to 700 animals, which attract visitors from around the world. Mule deer, California bighorn sheep and multiple species of birds of prey also inhabit the island.
Neka Roundy, secretary of the volunteer group Friends of Antelope Island, said though it may take some time to "overcome some of the burned areas," she doesn't think tourism to the park will be affected by the fire, once it's extinguished.
The state park anticipates 400,000 visitors this year, and Roundy said because the fire is mainly in the middle of the island people will still come to see the main attractions, which lie on the coast.
"Tourists will still be going there," she said.
Roundy also expects a strong effort to reseed the scorched land, which could be susceptible to erosion.
Officials believe the fire started by lightning sometime late Thursday, but didn't develop until about 5:30 p.m. Friday, Department of Natural Resources spokesman Shayne Ward said.
The island's bison herd seems mostly unfazed by the fire, Ward said.
"They are kind of moseying away from it," he said, of the herd, "They aren't running around."
The fire has been difficult to fight because of the island's rugged terrain and plentiful fuels, mainly grass and sagebrush.
Fire officials are asking people not to use drones near the island on Saturday because that would ground the fire's air resources.
The state recently adopted strict laws against the use of drones near wildfires, including criminal penalties.
Due to the fire, the island's campgrounds had been evacuated, hiking trails were closed and a Pioneer Day celebration scheduled for Saturday had been canceled.
Elsewhere, crews continued to fight smaller fires statewide Saturday, with significant gains.
The 90-acre Pole Patch Fire in Pleasant View was expected to be fully contained by 4:30 p.m., North View District Fire Chief Dave Wade said.
The fire started Friday in a field next to a gravel pit, near 4300 North and 1100 West. Investigators believe the fire was likely human-caused. Witnesses said a man on an ATV was in the field just before the fire started, Wade said.
Two homes were damaged, Wade said. One had its attic burned and the second suffered heat damage to a vinyl porch and siding. Wade estimated the combined damage at roughly $225,000.
Several outbuildings a barn and at least two sheds were destroyed or damaged, he said.
In Utah's West Desert, the 1,600-acre Choke Cherry Fire burning near Callao in Tooele County was 51 percent contained, a Bureau of Land Management news release said.
The Mercer Fire, was also burning in the Lake Mountains, west of Utah Lake. The fire was 27 acres and officials hoped to have it contained by evening, a tweet from the UtahFireInfo.gov said.
Another blaze in Millard County, the Lower Ebbs Fire, burned more than 500 acres Saturday night near Scipio.
Reporter Courtney Tanner contributed to this story.