RICHLAND — Weekend lightning storms sparked several wildfires over the weekend at Hanford, including one that spread over 9,000 acres.

None of the fires came close to any buildings or nuclear facilities.

The one large fire was at Gable Mountain in the center of the Hanford nuclear reservation.

The mountain is considered a tribal cultural and biological sensitive area, with workers not allowed there unless authorized.

It was contained at about 9,000 acres about 8 p.m. Sunday night, according to Mission Support Alliance, the Department of Energy contractor in charge of fire services at the site.

Hanford Fire Department remained on scene until Monday afternoon to watch for hot spots.

Windy weather and the steep terrain near the mountain were a challenge, according to MSA.

The 580-square-mile Hanford site was used to produce plutonium for the nation's nuclear weapons program during World War II and the Cold War. Environmental cleanup of radioactive and other chemical cleanup left from production years is expected to continue at the nuclear reservation for decades.