City remains faithful to its origins as a haven of luxury single-family homes.

Although star-studded neighborhoods such as Beverly Hills and Bel-Air have become symbols for the concentration of extreme wealth in Southern California, there are other neighborhoods here that are just as lavish but keep a low profile.

In the San Gabriel Valley, that market is San Marino, which was envisioned as the exclusive domain of the well-to-do from its inception.

Its founders — railroad magnate Henry Huntington and George S. Patton, a lawyer whose son would find glory on the battlefields of World War II — incorporated the city as a preemptive strike against annexation by neighboring communities.

Huntington was a longtime resident of the area. He had purchased a 500-acre working ranch where he built a palatial home and gardens, thanks to the proceeds of his vast interurban rail network, which knitted together the cities of the Southland decades before the first miles of freeway were laid down.

Patton was a scion of a family with a long tradition of military service and had come west to California at age 21.

After his marriage to the daughter of Benjamin D. Wilson, he and his wife became heirs to the pioneering Californian’s Lake Vineyard estate, which abutted Huntington’s ranch-turned-pleasure-garden.

Huntington brought the younger man into his circle, and eventually into his employ, and in 1913 the two would spearhead a campaign for cityhood to prevent their land holdings from falling under the jurisdiction of elected officials who did not share their extreme aversion to any type of land use aside from the building of luxury single-family homes. They were, in many respects, L.A.’s first NIMBYs.

Their philosophy lives, as enshrined on the city’s official website: “San Marino was formed to … control the growth and activities of the city” so that “property values will be protected by stringent zoning regulations.”

In that, they’ve been wildly successful. San Marino is the picture of genteel suburbanity; restrictive zoning has resulted in a cohesive environment free of the endless strip malls and stucco McMansions that plague parts of Southern California.

And true to their credo, the city’s elected officials have managed growth in such a way as to boost property values to the point where it’s a rare home there that lists for less than $2 million.

Neighborhood highlights Arts and culture: Henry Huntington’s estate is now a much-loved art museum and public garden, where generations of Angelenos’ visiting mothers-in-law have been treated to a stroll and high tea.

Agrowing diversity: Out — San Marino’s well-deserved reputation as a WASP enclave. In — the city’s burgeoning population of ethnic Chinese, many of whom hail from Taiwan.

Academic powerhouse: The San Marino Unified School District is among the best in the region, with top-rated schools from elementary through high school.

Neighborhood challenges

Sticker shock: San Marino is the most expensive market by far in the San Gabriel Valley, with prices as high as $13 million for homes near Lacy Park.

Few renters: Aside from luxury homes, there are few places to rent. The lack of apartments means that many San Marino workers can’t afford to live there.

Expert insight Marlene Evans of Coldwell Banker Residential said the city’s emphasis on maintaining its historical charm has reached the point where residents must post notices to addonto their homes.

“People are required to detail the scope of their project so neighbors aren’t stunned if a new garage or a second story goes up,” Evans said. “It’s all out there. No secrets.”

Because of this strict adherence to preserving its aesthetic, Evans said, the neighborhood has been able to avoid overbuilding. As other areas have allowed large homes on small lots, San Marino has managed to keep its historic feel, showcasing its array of English and Spanish-style builds.

“It’s an old city, and change doesn’t come very quickly,” Evans said. “There are only 42 homes for sale right now, so if you’re looking to make an offer, have your finances in order. It’s a very competitive market.”

Market snapshot In the 91108 ZIP Code, based on seven sales, the median sales price for single-family homes in January was $2.35 million, down 7.5% year over year, according to CoreLogic.

Report card Each of the four public schools in San Marino posted a score of at least 930 in the 2013 Academic Performance Index. Huntington Middle scored the highest, 977, and Carver Elementary scored 967.

Valentine Elementary and San Marino High scored 952 and 932, respectively.

hotproperty@latimes.com Times staff writer Jack Flemming contributed to this report.