They account for nearly one in three residents in both Cave Creek and Carefree, nearly double the concentrations seen in most of the rest of the Valley.

Scottsdale's median age of 41 in the 2000 census was third-highest in the nation among cities with more than 100,000 residents, trailing Clearwater and Cape Coral, two Florida retirement havens.

"That doesn't surprise me, partly because of the growing affordability gap here," said Rick Kidder, president of the Scottsdale Area Chamber of Commerce. "It is a concern as we go forward, as employers find it tougher and tougher to find employees within easy driving distance."

In Scottsdale, hair dye, cosmetic surgery and exercise may keep the middle-age generation looking younger than previous ones, but analysts say the graying trend will affect employment, housing, transportation, health care and even the character of other Valley communities.

Melanie Starns, policy adviser on aging to Gov. Janet Napolitano, said all of Arizona's communities have to be prepared for the state's aging population to ensure that there are enough health care workers, adequate transportation and other needed services.

Steve Bottfeld, a consumer research executive, said the urban-living condominiums attracting baby boomers from suburbia to downtown Scottsdale are the antithesis of the northwest Valley's retirement communities.

Baby boomers drawn to condos in vibrant urban areas like Scottsdale, Kierland and the Biltmore can live near restaurants, shopping and entertainment, said Bottfeld, vice president of Marketing Solutions, a Las Vegas-based firm with a Valley office.

Boomers, who once tweaked the "establishment" of their parents' generation, have ascended to management ranks themselves. That, along with tremendous inherited wealth, has brought them the kind of income needed to maintain a comfortable lifestyle in the northeast Valley.

Median home prices of $600,000 in Scottsdale and $1.67 million in Paradise Valley, plus the area's expensive new condos, suggest that wealthy boomers will keep migrating to the northeast Valley.

"Boomers are buying homes here while they're still working," said Bonnie Gentry, a Merrill Lynch financial planner in Scottsdale. "They are test-driving retirement and seeing if this is where they want to retire."

The Arizona Republic looked at demographics across the Valley. Boomers accounted for more than 620,000 of Maricopa County's 3.6 million residents in 2005.

In looking at the local boomer segment, The Republic used 2005 population data from Claritas, a marketing and demographic research firm, to arrive at boomer population estimates in more than a dozen Valley cities.

It showed a fairly consistent pattern of 16 to 18 percent in most cities, with a low of 14 percent in Surprise and much higher percentages in Scottsdale, Fountain Hills, Paradise Valley, Carefree and Cave Creek.

Surprise, with a population that recently topped 100,000, may have skewed younger because of a recent influx of young families to its new neighborhoods, spokeswoman Diane Arthur said.

Gary Neiss, Carefree planning director, said the town has never analyzed it, but he assumes that baby boomers are attracted to its lifestyle, which includes larger desert foothill home lots and a quaint, small-town commercial area.

In Scottsdale, the business community may be worried about its aging workforce, but one advocate says the city has a lot to gain from her post-World War II generation.

Cindy Cooke, director of Scottsdale Boomerz, a non-profit group that helps workers find jobs and volunteer positions, said that boomers bring experience, job loyalty and community activism to wherever they live.

Plus, many of them are not eager to stop working. A Merrill Lynch study this year revealed that three-quarters of boomers do not intend to seek a traditional retirement.

That includes leading-edge boomers like Dan Gruber, 59, of Paradise Valley, and Joni Millavec, 60, of Scottsdale. They are in a first wave of boomers redefining retirement.

Gruber, who retired two years ago from a management-consulting career, said he plans to continue with the conservation work "as a long I physically can."

Retiree Jon Hilsabeck, 56, of Phoenix, is already doing medical volunteer work. He helps patients at Scottsdale Healthcare-Osborn as a way of giving back to the community after 28 years of teaching history at Shadow Mountain High School in Phoenix.

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