Drivers passing the Rogue Valley International Medford Airport recently may have noticed some really big planes.

Drivers passing the Rogue Valley International Medford Airport recently may have noticed some really big planes.

Two DC-10s, the largest firefighting air tankers flying in the nation, have been using an upgraded air tanker capability there to fight fires in the region.

Medford is the only place in Oregon that can reload the DC-10s, with a portable base for what the agencies call “Very Large Air Tankers.” That, combined with the main base already in place, gives Medford more initial attack capability than ever before.

 Those bases have already provided about 500,000 gallons of fire retardant this fire season, more than twice the 235,000 average for an entire fire season out of Medford, according to the U.S. Forest Service.

The DC-10s can lay a swath of red fire retardant a mile long and 300 feet wide. That helps keep a fire in check while firefighters on the ground build containment lines.

“They lay a much longer line and they get to the fire quicker, that’s got to be a positive,” said Lonnie Allison, tanker base manager. “With two of those running, every time they drop, that’s two miles of line.”

The planes also carry 11,600 gallons of retardant, four times as much as the next-largest tankers, known as Next Generation. They also can fly at speeds of up to 563 mph, compared to 346 mph for the Next Generation tankers.

On Monday, the two DC-10s were flying to and from the Happy Camp Complex south of Grants Pass in California’s Klamath National Forest. It has burned 20,253 acres and is 20 percent contained.

The planes, first used buy the U.S. Forest Service in 2011, have also battled the July Complex farther south, which has burned 36,000 acres, and the Oregon Gulch Fire which burned over 30,000 acres along the California-Oregon border east of Ashland.

Allison said the two DC-10s were diverted south to a fire near Yosemite National Park on Tuesday, as smoke along the northern California fires made flying impossible. Two other tankers were grounded in Medford, he said.

Because the portable base for the large tankers can handle all types of air tankers, Medford essentially has two tanker bases this summer.

On Aug. 9, the two bases provided 90,000 gallons of retardant for two large fires, 40,000 gallons and 21 loads from the regular base, and 50,000 gallons and seven loads from the portable VLAT base.

On Aug. 11 the two bases cranked out 90,000 gallons for one fire, the Rogue River Drive Fire that threatened numerous homes near Shady Cove.

“The pilots coming back said they saved homes on that one,” said Virginia Gibbons, spokesperson for the Rogue River-Siskiyou National Forest. “They were pounding it.”