DENVER (AP) _ Skiers will skitter down snowy slopes across the land this holiday weekend as many resorts open their seasons, but industry executives say they are facing anxious times.

An aging baby boom population and increasing labor and insurance costs are squeezing the resorts, and operators are reaching out to new markets like families to try to stabilize the business.

Since the late 1960s and 1970s, the number of ski areas has declined from 1,400 to about 600, said Jerry Jones, executive vice president of the Vail, Colo., ski operation, which this year became the largest ski resort in the country.

The number skiers grew at double-digit rates during the 1970s, but the rate has slowed sharply since then.

In the past five years in just Colorado, a half dozen resorts have gone out of business, and up to half of the 28 ski areas remaining are thought to be struggling financially.

The smaller resorts, especially, ''have some problems, big problems,'' Jones said.

The National Ski Area Association has launched a major study it hopes will foster a national campaign to attract skiers, similar to generic ads that promote the coffee industry or dairy products.

Kathe Dillmann at the association said the business is just maturing after two decades of rapid growth, and said no one expected the industry to keep up its double-digit growth rate.

''This is a business,'' she said. ''This cycle is not the boom cycle now, but that doesn't mean it's not healthy. All businesses go through that. We have to look for our niche and see what the market is going to do.''

One of the biggest problems facing the industry is attracting new skiers.

''In the 1960s and 1970s the baby boomers grew with the industry,'' Jones said. ''Then the women started dropping out when they reached their 30s, and the men started dropping out when they reached their 40s. You just can't invent 17-year-old kids.''

As a result, ski areas have changed their emphasis to be more family- oriented . They provide child care, ski programs for youngsters and other winter-related activities such as sleigh rides and ice skating, in addition to restaurants and other amenities for the non-skier.

Jones says there also is a trend toward specialized ski resorts resembling theme parks.

''You can already see this happening,'' he said, offering several examples from his home state. ''Steamboat Springs is a Western ski resort, Vail is a Bavarian theme resort, Aspen is a Victorian theme resort. I think you'll see more specialization, such as a resort for the elderly, or for beginners only.''

A religious ski resort even has been tried, offering an alcohol-free environment and church services after skiing. However, the resort says it may close because of financial problems.

Stephanie Nora of Colorado Ski Country USA, which represents the 28 resorts in Colorado, said many resorts are offering innovative pricing to lure skiers, selling advance tickets through grocery stores and convenience stories, multi- day packages and other options.

''It's like taking a flight. No one calls up the day before going on a trip and says they want to pay full-price. They call up a few days before and say they want a discount,'' she said. ''That's what ski areas are doing.''

Jones said the loss of the smaller resorts is hurting the industry. Vail recently leased the Broadmoor ski area near Colorado Springs when the city had trouble making it financially.

''We're losing our farm-team organization,'' he said. ''These smaller ski areas in Iowa, Michigan, Illinois, Idaho and so on are closing their doors and eliminating the opportunities for the potential new skier to enter the sport. No one is going to go from Tulsa to Aspen for their first time skiing.''

He said larger resorts have a responsibility to the smaller resorts to ensure they survive. To do so, he said, they will have to create mega-resorts that encompass several ski areas, such as the complexes around Vail and Aspen in Colorado, Salt Lake City in Utah and Tahoe on the California-Nevada border.

The smaller resorts that are isolated probably will go out of business, Jones said. The shakeout has already begun, with up to 25 percent of the ski resorts in the United States being offered for sale, he said.

''I don't think there are that many buyers,'' he said. ''The Japanese have been all around Colorado, Utah and Canada looking for ski areas to purchase. But these are the long-term survivors they're looking at.''

Dr. Charles Goeldner, an assistant dean at the University of Colorado in Boulder who specializes in ski economics, is more upbeat than the operators.

He says the market is much healthier than it looks, noting that the number of skiers is still at an all-time high even though the rate of growth has slowed. He also notes an echo of the baby boom is beginning to emerge, with 4 million births a year creating a host of new potential customers.

''The resources are finite and there are only so many mountains,'' Goeldner said. ''Look at Europe and how high prices are there. They make our skiing look like a bargain. Fifty years down the road, our prices will mirror Europe.''