Photo courtesy of Cochise County Sheriff's Department

A fast-moving wildfire ignited by a lightning strike Saturday afternoon on ranch land near Elgin, about 55 miles southeast of Tucson, is now 65 percent contained.

No structures are threatened, authorities said.

The O’Donnell Canyon Fire had grown to 600 acres by Saturday evening, and had doubled in size in one hour, said Sonoita-Elgin Fire Department spokeswoman Katie Goodwin.

Three air tankers were dropping water on the blaze, which was being fought by about 100 personnel from multiple agencies.

A burnout operation was underway to prevent the flames from spreading.

The fire began shortly after 3 p.m. on the Babacomari Ranch south of the Mustang Mountains, and about 2½ miles north and west of Fort Huachuca, Goodwin said.

The fire, in Santa Cruz County, started in Sacaton Flats and moved into areas with other fuels.

Bridget Brophy, one of the family members who own the historic ranch, said while some cattle are in the general vicinity of the fire, none of the structures are threatened at this time.

The U.S. Forest Service, Arizona State Land Department and the Bureau of Land Management are assisting the Sonoita-Elgin Fire Department.

“We are moving to a unified command with the Forest Service,” Goodwin said Saturday night.

Contact reporter Darren DaRonco at 573-4243 or Follow on twitter @DarrenDaRonco