Firefighters on Monday mopped up remnants of blazes that charred nearly 2,200 acres in three Southern California counties, including one fire that destroyed six buildings and another started by boys playing with a toy rocket. No one was injured in any of the fires, officials said. In southeast Montana, hundreds of firefighters worked in 100-degree heat and winds of up to 25 mph to fight a wildfire that surged across 6,000 acres of grassland and timber on the Northern Cheyenne Indian Reservation Monday. Twenty smoke jumpers parachuted into the most difficult area at mid-morning, and officials called in a total of 400 firefighters during the day, said Keith Mosbaugh, fire boss for the interagency team trying to control the blaze. He said firefighters do not expect to contain the blaze before Thursday. No one was injured, Mosbaugh added. The fire broke out late Saturday or early Sunday and may have been caused by children playing with matches, said Mike Caprata, a fire management forester with the Bureau of Indian Affairs at Lame Deer. The cause was under investigation. The largest California blaze burned 1,800 acres on the outskirts of Desert Hot Springs, a community of 6,000 people 110 miles east of Los Angeles, said Cheri Hill, a dispatcher-clerk for the Riverside County Fire Department. Crews hoped to control the fire, or extinguish most of its flames, by Monday evening after more than 200 firefighters contained its spread 12 hours earlier, she said. The wind-whipped fire destroyed three homes and three other buildings and damaged another home, she said. The cause of the fire, which started Sunday afternoon in the center divider of Highway 62 about 4{ miles north of Desert Hot Springs, was under investigation, Ms. Hill said. Despite 15 mph to 30 mph winds, crews expected to control a 220-acre fire in the San Bernardino National Forest about 85 miles northeast of Los Angeles by Tuesday morning, after containing it at 8 a.m. Monday, said forest spokeswoman Lindsay Maierhofer. The blaze of unknown origin burned in dense pinon and juniper trees and destroyed an abandoned mining shack. It was reported early Sunday afternoon, and 390 firefighters, four helicopters and three air tankers were sent to the battle. A 170-acre brush and grass fire near the El Toro Marine Corps Air Station, 45 miles southeast of Los Angeles, was controlled at 9 p.m. Sunday, nearly seven hours after it was reported, said county fire department Capt. Patrick McIntosh. The fire was started by three teen-agers who were playing with a model rocket, he said. The three boys, ages 15, 16 and 17, were taken into custody and later released to their parents, McIntosh said, adding that ``the fire department will seek cost recovery from the parents for the firefighting operations. He said 150 firefighters fought the fire with equipment that included two fire-retardant-dropping planes.