BOISE, Idaho (AP) -- After containing a wildfire that scorched more than 300 square miles in southwestern Idaho, crews were working up and down the state Thursday on four other fires, the largest of which was at 4,000 acres.
None immediately threatened residences, but the North Hill fire near Bonners Ferry in the northern Idaho Panhandle forced the evacuation of 25 people late Wednesday as crews surrounded four luxury homes on a ridge while flames advanced up the slope through a stand of Ponderosa pines and Douglas fir.
''The crews that fought that fire did a fantastic job in stopping it prior to damaging any of those homes,'' Boundary County Disaster Services Coordinator Bob Graham said Thursday. The fire was 50 percent contained Thursday afternoon after burning 108 acres of pine forest.
The Monroe Creek fire on the Payette National Forest was expected to be contained late Thursday after burning 4,000 acres of tall grass north of Weiser in southwestern Idaho.
The Falls Creek fire 25 miles east of Challis in central Idaho had burned at least 125 acres in an area that was inaccessible to ground crews. And the Star Lake fire north of Eden in southern Idaho had been contained Thursday after burning 350 acres.
The increase in fires came as temperatures climbed into the triple digits across much of the state.
The National Weather Service issued a ''Red Flag Warning'' for a combination of dry lightning, gusty winds and low relative humidity that ''will create explosive fire growth potential'' across northeastern Nevada, southwestern Idaho, eastern Oregon, southeastern Washington and southwestern Montana through Friday morning.
Idaho Bureau of Land Management Director K. Lynn Bennett said the southern tier of the state is blanketed with tall grass and other fine fuels that grew heavily during a wet spring and have now dried out _ a possible accelerant for wildfires.
''Southern Idaho, like many areas throughout the Great Basin, is experiencing growth of grasses and brushy vegetation on a scale that many of us, and even some like me who have been around awhile, have never seen in our careers,'' Bennett said in a statement.
The state's largest fire this year, the Clover fire in Owyhee County, demonstrated the effect of the heavy loads of ''flashy'' fuels now covering rangelands.
At times, the fire that began Friday evening advanced across the sagebrush and range at speeds of 5 to 7 mph, burning 500 acres an hour. It was contained Wednesday after crews created 150 miles of fire line. The last firefighters were leaving the scene Thursday evening.
''If you were to drive the blackened area from the western end to the eastern end you would go 35 miles and if you went north to south you would drive 10 miles,'' said Sky Buffat of the BLM in Twin Falls. ''It's hard to fathom.''
A cause has not been determined for the Clover fire or the Falls Creek fire. The North Hill fire is believed to have been started by a passing train, the Star Lake fire is suspected as human-caused and the Monroe Creek fire began when part of a bird's nest touched two power lines.
Salmon-Challis National Forest fire managers were monitoring the Falls Creek fire as it burned in the steep terrain of the Pahsimeroi Valley late Thursday. A helicopter dropped water on the head of the fire as it advanced, but the terrain was too treacherous to send in ground crews.
''It's not doing much right now,'' said Gail Baer of the U.S. Forest Service in Salmon. ''If we can find a place where people will be safe on the ground and the weather is favorable, we are making a plan to take advantage of that opening, but at this time it's not posing any threat.''