KILLINGTON, Vt. - From the top of Vermont's Killington ski area, the allure of the backside of the resort's mountains is too much for some skiers and snowboarders to resist when the snow is deep. All too often, however, the trips across the resort's boundary in hopes of finding forests of untracked powder lead instead into a roadless wilderness.

In an effort to keep those skiers in bounds and avoid expensive rescue operations, Killington has opened up 745 acres of new terrain designed to give skiers the same back-country experience they'd get out-of-bounds. These trails go downhill to the base lodge instead of into the Coolidge State Forest, and trouble.

"Every season when the snow piles up, the locals go into the woods first. Once there are tracks out of bounds, the visitors will follow and some of them don't know their way around as well and that's when problems arise and they get stuck out of bounds," said Killington communications manager Michael Joseph.

So the resort created its Natural Woods, the ungroomed wooded areas between trails on Killington Peak that were opened to skiers this season as a direct result of the 15 operations mounted last year to rescue 49 individuals who skied or snowboarded off the backside of the resort and got lost.

"I think last year we kind of hit a point where something needed to be done," said Killington fire and rescue chief Gary Roth.

So far this season there haven't been any rescues at Killington. Officials say that's because of a lack of snow in the woods, not the new Natural Area. But heading into the President's Week holiday, the busiest week of the ski season, Roth, Joseph and others are holding their collective breath in the aftermath of a series of storms that have dumped copious amounts of fresh snow in the woods.

Michael Berry, president of the Colorado-based National Ski Areas Association, said Killington will find out over the next three weeks if demand for "off-piste" skiing will be satisfied by the new natural area.

Changes in ski equipment over the last several years, such as wider, shaped skis, has made it easier for people to ski in the back country. "That allows people to go places that only the absolute best used to be able to go," Berry said.

Skiing out of bounds is confronted by some western resorts, Berry said, because most are located on leased federal land and the back-country is open to the public, but it's not a major problem.

"There are always incidents that occur," Berry said. "There are always people who instead of turning right, turn left and go further afar."

Last year, partly in response to the spate of Killington ski rescues, the state of Vermont created a full-time search and rescue coordinator as part of the Department of Public Safety.

In the East, Berry and others said the issue is most extreme at Killington because the resort's topography leads people away from settled areas beyond the boundaries.

In Maine, the Sugarloaf ski area usually has a handful of rescues every season. For years, Sugarloaf has had a boundary-to-boundary policy where people could ski the ungroomed sections of the mountain if they wanted and several years ago they opened up 600 acres of back-country terrain.

"It's hard to say (if it works). We haven't seen a decrease in the number of searches, but we don't have nearly as many as Killington," said Sugarloaf spokesman Ethan Austin.

Murray McGrath, who has skied in the Killington area for almost 40 years, said he started skiing the back country because the resort got too crowded. Now he regularly takes his skis into the back country, sometimes riding the lifts and then skiing off the backside. Other times he and his companions will park a vehicle at their destination and then drive back to their starting point.

He's helped search for lost skiers and he's stumbled into skiers in the back country who didn't know where they were and directed them to the nearest road, in some cases more than 15 miles from the Killington parking lots.

"It will work for a little while, but then people are going to want to venture out because they'll figure out where the locals are going and say 'we want to get the real good stuff,'" McGrath said of the new natural area. "They have in their minds, 'there can't be anything good in bounds, it has to be out of bounds.'"