Campers and residents of another 60 homes were told to evacuate Tuesday after a fire in a wilderness area grew to about 23 square miles.

A day after residents of about 20 homes were asked to leave, officials ordered the evacuation of the additional homes in the Gates of the Mountains Wilderness. Campgrounds on the north shore of Holter Lake were closed.

• PHOTO ESSAY: Montana Wildfires Threaten 200 Homes

The latest evacuations were ordered after the fire "blew up" and crept to within a quarter-mile of one of the campgrounds, Lewis and Clark County Sheriff Cheryl Liedle said.

Meanwhile, in northern Idaho, an 81-square-mile blaze was threatening as many as 100 buildings but had been allowed to advance into the Hells Canyon Wilderness area, away from homes.

Crews made progress and fire lines appeared to be holding, Jodi Kramer, a U.S. Forest Service spokeswoman, said Tuesday evening. The blaze isn't expected to be fully contained until mid-October.

"We're feeling pretty good about the day," she said, adding that crews were preparing for a cold front with stronger winds later in the week.

In Montana, homeowner Lila Amato watched the exodus of evacuees from her camper, which she and her husband, Joe, had parked next to a Missouri River bridge "so we could stay close by and see what was happening."

The couple had been ordered to leave their lake home Monday night.

"It felt a bit silly, like we shouldn't be (evacuating), but I thought it's better to put all our stuff back whole than to take it out in pieces," Amato said.

• Monitor the situation in FOXNews.com's Natural Disasters Center.

The fire was about 30 percent contained Tuesday but was expected to grow to the north and northeast, said Bonney McNabb, fire information officer.

Large fires were also active Tuesday in California, Oregon, Washington, Wyoming, Michigan and Florida, the National Interagency Fire Center reported.

As of Tuesday, wildfires had charred 5 million acres, or more than 7,800 square miles, the center reported, compared with 5.6 million acres by the same date last year.

In Oregon, a TV news helicopter was blamed for interfering with a plane attempting to drop retardant on a wildfire, a Department of Forestry official said Tuesday.

Jim Ziobro, state aviation specialist and safety officer for the agency, said the pilot for Portland station KGW was told to remain in radio contact and stay at least 500 feet above the highest aircraft.

"He didn't do that," Ziobro said, adding that at times the helicopter was under the plane trying to make the drop. A report of Friday's incident was sent to the Federal Aviation Administration.

The KGW pilot, Daron Larsen, denied the accusations, saying that there was no temporary flight restriction in place when he arrived, and that without one, he has the same right to the airspace as the fire crews.

"I did not break any rules; I want to make that 100 percent clear," said Larsen, who said he has been flying news helicopters for eight years.