HELENA, Mont. - More than 42,000 lightning strikes were recorded across the Northern Rockies in a 36-hour period, sparking new wildfires in Montana and Idaho in addition to the dozens already burning across the region, fire officials said Tuesday.

But relief was expected to come later in the week, with temperatures forecast to drop across the region today and Thursday, and rain predicted to help firefighters in western and northern Montana.

At least one of those lightning strikes Monday resulted in a fire that quickly spread to 2,000 acres in south-central Montana about five miles north of Laurel, Mont. The Canyon Creek wildfire briefly threatened 256 houses before the wind died and firefighters set up protection lines on its southern perimeter.

Residents were put on standby and a shelter was prepared, but evacuations weren't necessary, said Duane Winslow, Yellowstone County's director of disaster and emergency services.

"At this point, there's nothing being threatened," said Winslow, who didn't have containment figures Tuesday night.

"I know they have the perimeter really well scoped out," he said. "I think they have it under control."

The Federal Emergency Management Agency said Tuesday it approved a state request and will pay for 75 percent of Montana's costs in fighting the Canyon Creek fire.

The lightning strikes from Sunday to Tuesday also started new wildfires in the Clearwater and Nez Perce national forests in Idaho, according to Bryan Henry of the Northern Rockies Coordination Center. There were at least three dozen active wildfires burning Tuesday in those two states and in northern Wyoming.

Tuesday was less windy and more humid for the large wildfires burning in south-central and southeastern Montana. That lull was an opportunity for fire crews to prepare for the weather front expected to settle just to the north on Wednesday and bring them 40 mph wind gusts, Henry said.

"Relatively speaking, it's a day for them to make progress," Henry said. "Tomorrow could be a more critical situation."

But to the west, Tuesday was already a critical day for crews working a 3,700-acre wildfire burning near Bonner, Mont. Red-flag warnings were in effect as 30 mph gusts were expected to combine with hot, dry conditions in the afternoon and push the blaze farther up the rugged terrain toward the fire lines dug in the day before.

No homes were in immediate danger, fire officials said.

The 682 people working the West Riverside fire made big gains on Monday, containing 45 percent of the blaze, and they hoped to hold on until the cooler weather arrived.

Rain and a 20-degree temperature drop were expected in the western and northern parts of the state Wednesday, part of the same weather front predicted to fan the fires to the southeast, Henry said.

More favorable conditions were expected to settle in across the state on Thursday.

"What helps us all out is the dramatic cool down. Everybody will be cool on Thursday," Henry said.

A possible exception is southwestern Montana, where the Saddle complex of fires burning nearly 24,000 acres on both sides of the Idaho-Montana line was still uncontained.

"Southwestern Montana could stay in the game after this front goes through, for a little while longer," Henry said.

Fire officials at the Saddle complex said crews are looking for new locations to build fire lines, but the rough terrain limits their options. Officials list 67 residences and two commercial properties as threatened, but no evacuation orders have been issued.

After a delayed start to the fire season, nearly 109,000 acres have burned this year in Idaho, Montana, North Dakota, South Dakota and northern Wyoming, Henry said. A typical year is between 160,000 and 180,000 acres burned. Much of that acreage has come in the last two weeks.

"We made up considerable ground in a short period of time," Henry said. "With the (weather) system coming in, we may end up just below normal unless we have some grass fires."