Fire officials said Wednesday crews have achieved 100 percent containment on the 440-acre Karney Fire in Boise County, which just a week ago was threatening more than 100 homes in the Robie Creek and Wilderness Ranch areas.

Two engine crews remained Wednesday to monitor the blaze, which officials say was lit by an 18-year-old volunteer firefighter early last week. One vacant home was destroyed by the blaze but fire crews were able to keep it from spreading to other homes in the area.

The Karney Fire was a major priority for fire crews last week. At one point, more than 300 firefighters on the ground were assisted by tanker planes and helicopters as they worked to keep the fire from getting into the Wilderness Ranch subdivision.

About 80 homeowners were given evacuation notices and roads in the area were closed to all traffic. The aggressive firefighting effort was assisted by cooler temperatures, light rain and higher humidity late last week.

Though all evacuation orders have been lifted and road closures have been removed, the public is urged to avoid unnecessary travel on Robie Creek and Wilderness Ranch access roads until the fire is out.

Forest rehabilitation work, like seeding areas where bulldozers put in firelines, will be done later this fall.

The Karney Fire started the afternoon Sept. 17, about five miles north of Highway 21, along Robie Creek Road in Boise County.

Boise County sheriff's say the blaze was started by Nathaniel Bartholomew, a member of the Clear Creek volunteer fire department who lives in the Robie Creek area.

Bartholomew is being held in the Ada County Jail on a felony charge of third degree arson. He has a preliminary hearing set for Oct. 1. Third-degree arson is punishable by up to 10 years in prison.

Sheriff’s officials say Bartholomew might have set the fire to get the attention of his father, also a firefighter. Boise County Chief Deputy Dale Rogers added that Bartholomew told investigators that working with his dad on fires was a bonding experience.

Bartholomew was identified as a suspect Sept. 17 after someone saw him walking away from where the fire started. Sheriff’s deputies found Bartholomew working the fire with the Clear Creek volunteers and took him into custody.