YELLOWSTONE NATIONAL PARK, Wyo. (UPI) - A greatly improved fire situation and mild early autumn weather has brought a second wave of tourists to the jewel of the national park system, but stiff winds Friday tested fire lines.

Park spokeswoman Linda Miller said all four entrances to the park and all roads in the park were open with the exception of the road over Craig Pass, which is undergoing construction.Campgrounds at Norris, Mammoth Hot Springs, Lewis Lake and Bay Bridge were open and at least one, the Norris facility, was filled to capacity, Miller said. Last weekend, the 2.2-million acre-park was devoid of tourists as a half-dozen fires raged out of control.

Miller said warm weather and south-southwest winds of 20-35 mph could spawn some renewed burning, but no major advances were expected.

"We'll probably have more increased fire activity today, but we're not anticipating any problems like we had last week because we've been able to strengthen the lines during the cool weather," Miller said.

The park headquarters had been threatened last week by the Wolf Lake fire, a northern finger of the 335,600-acre North Fork fire.

In eastern Yellowstone, Fire Information Officer C.D. Bylander said the 416,500-acre Clover-Mist fire ranged from 70 percent contained on its northern half to 80 percent in the south.

"That area didn't get much precipitation in the past week and with gusting winds and warmer temperatures there could be some fire spotting up in that area," Bylander said. "Today will be a test."

The 107,300-acre Storm Creek fire in the northern portion of the park was completely contained.

A force of 6,700 firefighters in Yellowstone, augmented by two battalions of U.S. Marines, took advantage all week of cooler, wet weather to dig fresh lines that should check any wind-driven advances.

Fire bosses also looked forward to another system which could bring more rain and snow to the region as early as Sunday.

Throughout the West, this has been a banner week for firefighters, with 21 major fires contained in the past five days. However, 15 fires were still active and uncontained on a total of $,736,948 acres, or more than 2,713 square miles. About 30,000 firefighters remained on duty.