DULUTH

Torrential autumn rains have brought an end to the forest-fire season in northeastern Minnesota, the driest, most destructive year since 1918. But the fire danger in the blow-down area of the Boundary Waters Canoe Area Wilderness hasn't gone away.

The destructive Ham Lake fire in May hardly touched the areas where a July 4, 1999, windstorm knocked down millions of trees in the BWCA and nearby areas of the Superior National Forest. It burned only a few hundred acres of blow-down.

A Duluth News Tribune review of U.S. Forest Service data shows that more than three-fourths of the blow-down in the area remains unburned and uncut, mostly in the BWCA.

The Ham Lake fire started May 5, apparently from an unattended campfire, and burned almost 119 square miles in Minnesota and Ontario.

The U.S. attorney's office in Minneapolis is still deciding whether to pursue criminal charges or to seek civil damages against the party that investigators believe is responsible. Jim Sanders, supervisor of the Superior National Forest, said law enforcement investigators are in contact with federal prosecutors, but there's no indication if or when charges might be brought.

Despite the dry conditions, no fire bans were in effect when the Ham Lake fire started because it was so early in the camping season.

The Minnesota part of the fire was the state's largest and costliest forest fire since 1918.

About 140 structures in Minnesota and 15 in Canada were lost. Heroic efforts by fire crews and local residents are credited with saving dozens more. Nobody was seriously hurt.

In contrast, the 2006 Cavity Lake fire stayed within the undeveloped wilds of the BWCA. It burned more than 20 square miles of blow-down.

The Forest Service has burned another 40,000 acres of blow-down, but the 1999 storm toppled trees across nearly 781 square miles in and around the Superior National Forest. Less than 23 percent of the blow-down area has been burned or logged to reduce the fire danger, the News Tribune reported.

"If we've learned anything in recent years, with fire behavior we've seen up there, it's that the blow-down's legacy [for fire] is going to be with us longer than we originally expected," Sanders said.

Instead of 10 years of elevated fire danger ending in 2009, as once expected, Sanders said the danger will stay elevated through 2017 or longer because of all the dead timber out there. "It's still standing, still drying out. It's not rotting, not decomposing," Sanders said.

The remaining trees are big and won't start on fire easily. But a few weeks without rain would dry out the forest floor, creating a ladder of leaves, brush and small trees that could carry fire into the dead trees as well as live trees.

Sanders said western parts of the forest, closer to Ely, have been mostly spared by fires in recent years, citing luck and fast action by firefighters. That could change during any dry spell, he said.

However, a nearly two-year drought seems to have broken in September and October. Near-record rainfall has helped streams, swamps and lakes refill to normal levels or higher.

And the Forest Service is more than halfway toward its goal of purposely burning 109 square miles to create a strategic series of firebreaks across the blow-down area. The 2006 Cavity Lake fire burned nearly 20 square miles of downed trees that the Forest Service was going to light on its own.

With good weather -- not too wet or too dry -- the plan could be completed next year, said Ellen Bogardus-Szymaniak, former fire and fuel expert for the Superior and Chippewa National Forests.