Light rain during the night gave firefighters a boost Sunday as they strengthened their attack on a wildfire in Yellowstone National Park.

Firefighters had contained about 25 percent of the fire, up from 15 percent in previous days.

Crews hoped to take advantage of higher humidity on Sunday because hotter, drier weather was predicted in the coming week, fire spokesman Dave Turner said.

"There is much ground to gain if they really pour it on," he said. "And bottom line, they're much more efficient when it's cooler."

Firefighting efforts were focused on keeping the fire away from Yellowstone's east entrance and U.S. 20, which extends through the park, Turner said.

The east entrance had been closed for eight days and the fire remained half a mile from employee housing.

Fire spokesman Justin Dombrowski said he expected progress to slow in the next few days because the firefighters will be working in very steep terrain.

About two miles from the east entrance, firefighters rather than tourist were filling the Pahaska Tepee resort, part of which was built by Buffalo Bill Cody in 1904.

"All our rooms are taken up by pilots and crews," said resort co-owner Angela Coe.

Elsewhere, firefighters were confident they had the upper hand on a blaze on the Wyoming-South Dakota state line. Two wildfires in the Black Hills had charred about 34 square miles since July 27.