In the case of Denali National Park and Preserve, the number of people trying to climb Mt. McKinley has doubled since the mid 1980s. Officials estimate 1,250 climbers have set out for the top so far this year. “When you have that many people concentrated in an area, you have obvious concerns about waste and congestion,” says park planner Mike Tranel.

The good news is that efforts of park administrators to remind visitors of their ecological responsibilities finally have begun paying off.

“In recent years we’ve been telling people to pack out their trash, but there’s been no enforcement,” says Tranel. “Now we’ve begun handing out trash bags and urging their use, and people are complying. It’s cleaner this year than it’s been in 25 years.”

The human waste issue is a bit trickier. As of now, it’s perfectly legal to simply bury the stuff—or put it in a bag and toss it into one of the many ice crevasses that make this mountain an especially interesting place to climb. But that could change.

“We’re not sure how sustainable that practice is, so we’ve been experimenting with carrying it out,” says Tranel. “Some of the volunteer and ranger climbing parties have used a portable plastic thing that you use for solid waste, similar to what’s used on rafting trips in the Grand Canyon.” Eventually, packing it out could become mandatory.

LITTLE GROUSING ABOUT NEW REGS

Such inconveniences notwithstanding, so far there’s been little grousing about the park’s lengthening list of regulations. These include a 60-day advance registration for climbers, along with a fee of U.S. $150, which is used mostly to support educational activities. There’s been considerably more of a fuss over proposals to limit the use of snowmobiles in the park.

In April, the National Park Service banned recreational use of snowmobiles at almost all national parks, monuments, and recreational areas, including Yellowstone National Park in Wyoming—where fans, the industry, and a group of Western senators put up a bitter fight. Also prohibited last year were the use of personal watercraft such as Jet Skis from most park system areas.

Opponents of the ban called it a planned campaign by the Clinton administration to limit access to public lands, and warned that while snowmobiles were on the Park Service’s unwanted list today, campers and sport utility vehicles might be next. But the government stuck to its guns.

“Snowmobiles are noisy, antiquated machines that are no longer welcome in our national parks,” said Assistant Interior Secretary Donald J. Barry. “The snowmobile industry has had many years to clean up their act, and they haven’t.”

However, the story was different in Denali—the Athabascan Indian name for Mount McKinley. Under terms of a 1980 law that roughly tripled the size of the park, certain activities considered “traditional”—such as hunting and gathering by native and rural Alaskans—remained legal. These activities included the use of snowmobiles, which were important for such purposes as hunting and traveling between remote villages.

SNOWMOBILES LIMITED

Since then, snowmobiles have become a popular sport, a lucrative industry, and a thorn in the side of environmentalists and others who visit parks in order to get away from the sound of engines—especially ones that sound like chainsaws. The National Parks Conservation Association estimates that more than 180,000 snowmobiles are used in the National Park System each winter. Each one can emit the same level of hydrocarbons and nitrous oxide as 1,000 cars, according to the Wilderness Society.

Despite court challenges, officials at Denali last month finished closing to snowmobiles the one-third of the park that is designated as wilderness. They are now considering reductions in other parts of the park.

“It’s not our intention to eliminate them entirely,” says Tranel. “But it should be related to some resource value of the park: scenery, solitude, wilderness, wildlife viewing. If you want to do it for play, like to see who can make the highest mark on a steep slope, maybe you should do it somewhere else.”

Officials expect to have a draft plan dealing with this and other issues—such as possibly limiting airplane landings and overflights—by next winter, with a final version in place by summer.

Eye in the Sky is a weekly series that brings you the story behind the headlines using satellite imagery, remote sensing, aerial photography, and maps. This feature is developed by National Geographic News with the sponsorship of the National Imagery and Mapping Agency (NIMA) and Earth-Info. Check out maps and imagery at http://www.earth-info.org.