SELMA — Firefighters are employing a ground and air assault to stop the advance of the 625-acre Horse Mountain fire before it enters dead timber burned by the 2000 Biscuit fire.

SELMA — Firefighters are employing a ground and air assault to stop the advance of the 625-acre Horse Mountain fire before it enters dead timber burned by the 2000 Biscuit fire.

Using five helicopters to drop water on the flames and hundreds of hand crew personnel on the ground, the goal is to stop the fire's advance before another weather front moves in late today.

"We are still establishing containment lines," explained Brian Mattox, a U.S. Forest Service employee from southeast Utah supervising one firefighter division.

"The dampening rains gave us a toehold," he said of limited rainfall early last week. "But we need to finish the work before the next front comes in. We are not ready for it to test us yet. We're kind of on edge about the new system coming in."

The weather front predicted by the National Weather Service will bring wind, potentially fanning the flames of the fire burning in the Wild Rivers Ranger District of the Rogue River-Siskiyou National Forest some 17 miles southwest of Grants Pass. The fire was sparked by an Aug. 16 lightning storm.

"We're starting to see increased fire behavior," Mattox said Saturday afternoon. "With the incoming front, we are real concerned about the wind and how hard it will push this fire."

Although the forecast calls for a 30 percent chance of rain on Monday, hot and dry weather is expected the remainder of the week.

In addition to the potential for more wind, firefighters are concerned that the Horse Mountain fire might start torching standing but dead trees in the area burned by the 2002 Biscuit fire. At its closest point, it was within 1,200 feet of the Biscuit fire area on Saturday.

"If it hits those dead trees, we could have increased fire behavior," said Brett Blumhardt, a U.S. Bureau of Land Management employee from northeast Wyoming working with Mattox.

But he is optimistic the firefighters can hold the line.

"We're getting a lot of line put in but we'll see what the weather brings," he said. "We're doing well so far."

"Our goal is to not let it reach the Biscuit area," Mattox stressed.

About 600 people have been assigned to the 645-acre Wild Rivers complex fires, which include the large Horse Mountain fire and the much smaller East Fork and Whiskers fires.

Meanwhile, on the northern end of the forest in the High Cascades Ranger District, the 500-acre Lonesome fire near the Rogue-Umpqua Divide is moving slowly, officials report. The fire has burned into the Rogue-Umpqua Divide Wilderness near Buckneck Mountain, where minimum-impact suppression tactics are being used by the 120 firefighters assigned to that fire.

The 150-acre Bessie Rock fire some eight miles east of Prospect had not grown in the 24-hour period ending Saturday evening. It was expected to be contained by a fireline by this morning.

Reach reporter Paul Fattig at 776-4496 or e-mail him at pfattig@mailtribune.com.