Bob Rosso has had to make many accommodations to the past during the past three decades as he expanded his backcountry equipment retailing and rental business from its beginnings in the 1882 home of one of central Idaho's pioneers.

"There aren't many of these old buildings left," said Rosso, who owns the Elephant Perch in Ketchum. "It would have been easier to knock it down. But we wanted to retain the history. It's an inconvenience to maintain all these little spaces, but it has something special about it."

Rosso's view, however, is being increasingly challenged with the disappearance of other buildings that mark the town's beginnings as a mining center and its transition into an early 20th century livestock hub -- victims of Ketchum's evolution into a playground for the wealthy where property values are rising 10 percent a year.

"In the past three years we were amazed at how many buildings that were on our historic inventory were gone," said architect James Ruscitto, chairman of the newly reconstituted Historic Preservation Commission. "It's a reawakening for the city. Property values have gotten to the point where they're knocking down almost-new buildings for development."

The problem isn't peculiar to Ketchum and the Sun Valley resort a mile down the road. Critics say it haunts the entire West, where rapid population growth has fueled skyrocketing property values that jeopardize historic properties and the region's way of life.

"We have a responsibility to future generations to save buildings so they can have that physical connection with their history," said Michael Buhler of the National Trust for Historic Preservation.

The trust's list of historic sites in jeopardy is long and varied. It includes the Willits, Calif., ranch where the horse Seabiscuit was rehabilitated in 1939. It covers historic neighborhood schools victimized by deferred maintenance. It holds inner-city churches, highlighted by the fight in downtown Seattle to put a high-rise office tower on the site of the century-old First United Methodist Church.

"When it comes to dollars and cents, it's difficult to convince individuals and corporations that there is a value to the historical significance of buildings or sites that outweighs the financial value," Idaho State Historical Society Executive Director Steve Guerber said. "Where property values are really skyrocketing, that's putting pressure on historical buildings."

The reality of value vs. history is no more evident than in Ketchum, where land in the city core sells for about $125 per square foot.

The Bald Mountain Hot Springs Hotel, built in 1929, was a central attraction with its pool filled with hot water moved through wooden pipes from a natural hot springs two miles away.

"It was the focus of Ketchum," said Mary Jane Conger, whose family helped settle the area.

But the lodge was sold and moved to a ranch 100 miles south and the cabins were being removed to make room for an 80-room hotel when the project's financing fell through. Now the lot is back on the market for a reported $6 million.

"An interesting historic building is gone and now we have a half-vacant lot," Ruscitto said.

Local history enthusiasts, led by Conger and real estate agent Anne Zauner, are trying to come up with a plan to at least save the cabins that are left, possibly converting them to office space.

"We're starting to realize that we do have a history here, a rich history and if we don't save it, we're going to lose our character," Zauner said.

While wealthy patrons occasionally save buildings because they do not need more money, real estate agent Dick Fenton said there are few such cases.

Fenton's office is next to a 5,000-square-foot lot worth about $600,000. On it is a 750-square-foot log cabin built in 1938, which is now a restaurant paying relatively low rent.

"It's a 4 percent return so you're not going to hold it," Fenton said. "If you're looking at it from an investment point, you'd build an office building with condos on top."

"The difficulty is you're a landowner sitting on land that's worth so much," Fenton said. "You need incentives. It has to be in the interest of the landowner. He says, 'All my money's tied up in this funky little house that you call historic and I call barely habitable.' " There are limited incentives -- a federal tax credit and some grants. But Ruscitto and others agreed that there isn't enough money to offset the cash that development usually generates. Preservation has to be something done for its own value, they said, and fostered by community support for history.

Some communities have used zoning ordinances to prohibit demolition, though Fenton said that in the case of many old buildings that kind of restriction on private property rights would not hold up in court. One option, he said, is letting landowners sell their development rights to others, who could then increase the density of their developments beyond what would otherwise be allowed. But that market has yet to take hold, he said.

Ruscitto said there are other ways to accommodate development plans for the sites of old buildings without destroying the buildings. They could be converted to contemporary uses such as stores or offices. Or zoning laws could be used to require at least some investigation into an old structure's history before demolition is considered. Owners could be advised on any incentives to help offset gains from demolition.

The preservation commission is also putting up plaques on preserved buildings, identifying the original use and the construction date.

"Just having people see these buildings turned into shops and restaurants is important," Ruscitto said. "You can't stop progress, but there are many ways to pay respect to these buildings."

Downtown Ketchum, Idaho, includes many buildings that date to the 1880s. The land on which they sit is very valuable.