About three years after betting big on ski resorts, Fortress Investment Group LLC is selling a large Colorado ski area and trimming its exposure to an industry that has seen demand chilled by the financial downturn.

The Copper Mountain Resort ski area is one of several that Fortress acquired in 2006 when it bought Intrawest Corp., a Canadian owner of North American resorts, luxury golf courses and leisure travel businesses for $2.8 billion in cash and assumed debt. Last year, Fortress restructured some debt related to Intrawest.

Copper Mountain, a resort with 22 chairlifts about 75 miles from Denver, is being purchased by Powdr Corp., a closely held Park City, Utah, company that owns seven other ski resorts, including Park City Mountain Resort in Utah and Killington Resort in Vermont. Representatives of Fortress and Powdr declined to comment on the sale. But a person familiar with the property said Powdr paid more than $100 million. The deal is expected to close before year’s end.

The deal, one of the biggest sales of a ski resort since the financial crisis, provides a glimpse into the current value of such properties that have been suffering from declining revenue and visits. It isn’t clear why Fortress and Intrawest decided to sell Copper Mountain when the ski business is so weak.

Near the peak of the market in about 2006, ski resorts traded at prices close to about 10 times earnings. Prices for resorts these days are more likely to be in the seven-to-eight multiple range, according to Jerry Jones & Associates a brokerage in Avon, Colo.

An Intrawest spokesman said the company wanted to focus on its core resorts, but declined further comment. Some analysts believe the move was part of a debt-reduction strategy. “No one wants to sell anything if you don’t have to now,” said William Marks, a managing director with JMP Securities in San Francisco.

While the market rally has helped Fortress’s performance, the deal comes as Fortress has been struggling with other souring investments and weak results. For the three months ended Sept. 30, the firm posted a loss of $190 million.

The big question facing Powdr and the ski industry: When will the market for new condo and commercial development recover?

The industry saw the number of skier visits fall to about 57.4 million in the 2008-2009 season, down about 5.1% from the 60.5 million visits logged in the year-earlier season, according to the National Ski Areas Association. Steep discounting by ski areas and special promotions such as free ski lessons are widely believed to have resulted in substantial drops in revenue.

At the same time, the real-estate market in ski-resort areas also is feeling the pinch as fewer mortgage companies are interested in financing second homes or investment properties, according to Brooke Roberts, director of sales at Denver-based Land Title Guarantee Co. The Copper Mountain area saw the total volume of property transactions completed this year through September fall to about $20 million, from about $40 million in the year earlier period, Ms. Roberts said. That total includes condominiums, single-family homes, commercial property and land.

The average price of condominiums and townhomes sold this year in Summit County, where Copper Mountain is located, from January through September was about $394,784 this year, down from about $463,633 for all of 2008, Ms. Roberts said.

Intrawest owns and operates Copper’s on-mountain operations such as the ski lifts, ski school and the base village. It also has a permit from the U.S. Forest Service to operate on about 7,343 acres, which will need to be reissued to the new owners.

Intrawest purchased Copper Mountain in the mid 1990s for a price that was reported at the time to be in the $192 million range. At one point Intrawest owned about 480 acres in the Copper Mountain area, said Rob Pyzel, a senior planner with the Summit County Planning Department. Intrawest has since sold some of that to developers, but Mr. Pyzel said it still owns a majority of the property, which includes the base village, a golf course, open space and approvals to develop additional residential and commercial property.

Copper Mountain, whose name reflects its mining history, has its own following and is viewed by some as offering a down-to-earth vibe that is more popular with retired executives and their families rather than the movie stars that often frequent Vail or Aspen, Colo. “It’s striving to be destination resort but the reality of life is Copper is an extremely good ski mountain that is loved by the Denver crowd,” said Tom Malmgren, owner and president of Carbonate Real Estate in Copper Mountain.

Write to Maura Webber Sadovi at maura.sadovi@wsj.com