The Mother Lode is getting grayer by the day.

Tuolumne and Calaveras counties, home to thousands of rough-and-tumble young miners during the Gold Rush, now attract fortune seekers of a different kind. The new prospectors are retirees looking for a beautiful, affordable place to spend their golden years.

The so-called "equity immigrants" have been migrating from the Central Valley and Bay Area for years and have helped lift the median age in both counties above 43 among the oldest among the state's 58 counties.

According to the U.S. Census Bureau, nearly 20 percent of us are on the far side of 65.

Don't expect this trend to reverse itself: Contrasted with cities, particularly in the Bay Area, housing and living costs in the foothills are attractive and the lure persists.

At the same time seniors move in, many young people move out. Homes and jobs are hard to find here for those just starting careers, and many go elsewhere perhaps to valley counties with median ages in the 20s to begin their work lives.

The demographic shift is a sea of change for the two counties and one that brings opportunities, responsibilities and problems. Two of the problems hit the headlines last week:

? Meals on Wheels programs in both counties, faced with rising costs, have cut services. Tuolumne County is discontinuing the frozen meals it had delivered to homebound seniors to get them through weekends. Calaveras County, which once delivered hot meals daily to shut-ins, has gone all frozen and now delivers only once a week.

? Tuolumne County's money-losing Adult Day Health Care Center, where up to 40 seniors spend weekdays with friends and a professional staff, will close at the end of the year. Unless a new operator is found, clients will be on their own and perhaps forced to pay far more for assisted care.

There are solutions: A Railtown benefit raised thousands of dollars for Tuolumne County's Meals on Wheels Saturday and a new nonprofit organization may take over Adult Day Health Care next year.

These won't be the last crises our seniors will face. Problems may multiply as Baby Boomers age. Not all can afford the health care required and some, perhaps after losing spouses, are alone and isolated.

Affordable medical care, public transportation and adequate housing, according to a Tuolumne County Commission on Aging survey, are already key priorities among our seniors. Providing them will be challenging, but could be a boost for the local economy.

Life expectancy has increased dramatically in a generation, and today's seniors remain vibrant and active for years after retirement. "Sixty is the new 40" has become more than a saying, and many of those coming to Tuolumne and Calaveras counties have the money and the energy to live retirement to the fullest.

Builders and subcontractors may be key beneficiaries. With proceeds from the sale of previous homes and from retirement accounts at the ready, many are shopping for more than starter houses. New subdivisions in both counties seem tailor-made for this market.

For those wanting closer-knit communities, senior developments like Sonora Hills and Murphys Diggins are already thriving.

Active seniors pay taxes, shop, eat out, go to shows, hire carpenters, plumbers and landscapers, and enrich our communities with their volunteerism, wisdom and experience.

Certainly we should not abandon efforts to attract and keep young professionals and families. They are the future of our community.

But senior citizens are already here and more are coming. Doing our best to welcome them and meet their needs can be a winning proposition for both our newcomers and our economy.