Take exit 430A from Interstate 35 in Dallas, then drive north on Oak Lawn Avenue, and you will eventually come to the Ashley Priddy Memorial Fountain, a burbling, five-tiered, stone-and-tile sentry that signals your arrival in Highland Park. As you cross Armstrong Parkway—named for John S. Armstrong, the meatpacking titan who purchased Highland Park’s original 420 acres in 1907—Oak Lawn becomes Preston Road. You’ll notice that the street signs are now blue. A bit up the street, past the $24 million home of real estate scion Harlan Crow and—tap the brakes—the 4400 Preston residence of Cowboys owner Jerry Jones, is Highland Park Village, the most gorgeous strip mall you’ve ever seen. Art deco buildings house Ralph Lauren and Jimmy Choo, and at the Starbucks on the corner, you might just catch a glimpse of the newly single Troy Aikman. His six-year-old Spanish-tiled home on Highland Drive is for sale, by the way, priced at $24 million.

Welcome to the honeypot of Dallas real estate, MLS Area 25, known to the layperson as Highland Park and its sister neighborhood, University Park. Laid out by the same urban planner who carved the avenues of Beverly Hills, these twin incorporated cities attract billionaire bankers like Gerald J. Ford, art collectors like Deedie and Rusty Rose, and philanthropists like Nancy
 Cain Marcus. Here, the winding, tree-canopied roads—patrolled by SUV-driving cops with the zeal of Stasi agents—boast names like Versailles Avenue and, respectfully, Beverly Drive. In one select enclave named Volk Estates, the lots are typically one acre, larger than anywhere else in the area, and go for some of the highest per-square-foot prices in the state. The schools are always exemplary and lacrosse-obsessed, regardless of budget cuts in the Legislature. During the holidays, the mansions feature jaw-dropping light shows, best seen from a horse-drawn carriage you can book at Highland Park Village.

In the world of Texas real estate, nothing quite compares to the Park Cities. There are other A-list neighborhoods, of course: River Oaks, in Houston; Pemberton Heights, in Austin; Alamo Heights, in San Antonio. But the concentration of billionaires in Dallas (according to this year’s Forbes 400 list, the city is home to the second-highest number of them in the country, after New York), coupled with the density of the Park Cities (close to four thousand homes per square mile), makes this an unparalleled nexus of power and wealth. Despite a slumping economy and a moribund housing market, Highland Park and University Park still enjoy some of the highest home prices in the United States. In MLS Area 25 the price per square foot in August 2011 averaged $341, with the average home priced at $1.2 million. (A square foot in River Oaks goes for roughly the same price, whereas one in Beverly Hills goes for nearly double.)

One morning this past August I find myself staring up at one of these high-dollar exemplars of the American dream, a stately English Tudor on Bordeaux Avenue. I happen to know from real estate chatter—which, in the gossipy world of Dallas, is practically a contact sport—that this is the new residence of one Jerry Jones Jr. The never-lived-in house, bought in June, is reported to have six bedrooms, eight full bathrooms, and four half bathrooms—plenty of space for lots more Dallas Cowboys progeny. I also know that the 14,000-square-foot, four-story castle (four-story is, evidently, the new three-story) is twice the square footage of Jones’s previous home, a few blocks away, though speculation was that the real trigger for him was the nine-car underground garage (the other new thing: going subterranean). And the price? Originally listed at $13 million, the half-acre estate was blue-lighted to $8,975,000.

The realtor who listed this particular home was Erin Mathews, a blond-bobbed, model-thin 62-year-old who belongs to an elite circle of Dallas agents who sell properties to the city’s most moneyed, bold-faced names. Mathews, who has worked in the Park Cities for nineteen years, is well acquainted with these private drives and hedge-lined roads. I know this because she’s my tour guide.

“There are no secrets in real estate,” she bemoans loudly, as we cruise by the house in her diamond-white Mercedes. It’s been a month since Jones moved in, and Mathews is still annoyed by all the online buzz about the sale, though she does acknowledge the (literal) desire to keep up with the Joneses. “Everybody in Dallas wants to know where they stand in the universe.”

Mathews gently presses the S-Class accelerator. Her lengthy, Jazzercised legs end in glittery Christian Louboutin pumps. Her BlackBerry nags. It’s the seventh marimba chime in fifteen minutes. “My clients love to text,” she tells me. “And they want an answer immediately.”

From the car, Mathews points out the home of billionaire Sam Wyly and a limestone Italianate she sold last month. We pause for a trio of power-walking moms in flawless makeup and sports bras crossing the street with their strollers. Driving in the Park Cities is like entering a space-time continuum where wrinkles or double-dip recessions don’t happen. (Or droughts: on this 108-degree day, as flashing signs along the interstate read “Conserve Water,” sprinklers continue to douse the fairways of the Dallas Country Club.) A morning here might include a stop at Hermès, nonfat latte in one hand and a Wall Street Journal in the other, the financial Armageddon headlines ignored. S&P downgrade? What’s that?

Entrée to this paradise requires a certain credit limit. But it also requires the help of its gatekeepers, a cadre that includes legendary realtor Ebby Halliday, who celebrated her one hundredth birthday this year; her golden boy, Dave Perry-Miller, who is said to have sold the most expensive spec home in Dallas, listed at $12.5 million; society agent Doris Jacobs, whose slogan is “The Name to Know”; Allie Beth Allman, who sold George W. Bush his home; and, of course, Mathews herself, who works in partnership with her former competitor David Nichols.

In the self-conscious circles of the Park Cities, Mathews’s personal style stands out: the statuesque agent, whose preference for Ralph Lauren Purple Label was featured in Vogue in 2008, certainly dresses like someone who’s sold 26 listings with an average price of more than $2 million in the first half of 2011. But it’s her understanding of (and patience for) the whims of the rich that keeps them returning, house after house. When Bravo execs call her office with reality show pitches, which they do with increasing frequency, Mathews turns them down. “My clients are busy,” she tells me. “That kind of television is not their style.” She and Nichols do produce a glossy catalog of listings named M|N Home that features portraits of toothy associates and full-page ads purchased by car dealerships. “But it’s more about the clients,” she says, noting that her firm doesn’t have big yard signs emblazoned with her likeness. “This is not the Erin Show.”

We pull up to the curb outside an imposing chateau at 4260 Bordeaux, and she nudges down Chanel aviators before glancing at her phone. “The home that used to be here was a teardown. A big, monster home,” Mathews says, looking up and tap-tap-tapping the window with a nail polished a soft beige. She sold the house in 1994, her second year as an agent. The multimillion-dollar sale was Mathews’s first big-ticket transaction and placed her at the periphery of powerful Dallas brokerage owners like Halliday and Allman. Today Mathews sells plenty in adjacent areas, such as Uptown, Greenway Parks, Bluffview, and the prestigious Preston Hollow, where Bush, Mark Cuban, T. Boone Pickens, and Tom Hicks live. Like any good agent, Mathews can reel off precise data for each neighborhood: prices, stats, whom to know, the best lunch spots, and where to find an iced-tea lemonade slushy (City Café, on Lovers Lane). But it’s the Park Cities, where she has lived for most of her time in Dallas, that she knows most intimately.

We stop in front of a house she just sold on Gillon Avenue. This is one of Mathews’s favorite streets, a lane flanked by live oaks and sculpted hedges. She’s sold many homes here. The 10,000-square-foot, pink-bricked house before us went to a family with young children. We drive away, and as we turn left onto Lakeside Drive, Mathews points out several large stone teddy bears on the other side of a small lake, a Christmas gift to Highland Park from the Crow family. Some of Mathews’s most satisfying sales, she tells me, are to growing families. “I’m a happy ending kind of girl,” she says.

And right now, there may be no place in Texas with more happy real estate endings than MLS Area 25.

The high-end home market in Dallas escaped the country’s economic woes relatively unscathed—it never received the near-terminal diagnosis given to Miami or Las Vegas—but that’s not to say it didn’t experience its own crisis related to the downturn: an abundance of leftovers created by speculative building. “From 2004 to 2007 we had custom builders in the Park Cities and Preston Hollow buying teardowns and paying huge numbers for the lots,” says Ted Wilson, the owner of the Dallas-based consulting firm Residential Strategies. “That translated to three- and four-million-dollar houses. Each one got higher. Then the next. Around and around we went. Then the music stopped.”

As credit tightened and lenders pulled back on fixed-rate mortgages, some builders were left without a chair. By 2008, with the collapse of the credit and equity markets, many of those spec houses were being unloaded at lower prices, with discounts of up to 20 percent. (Of course, that still meant sales of $2 million.) For realtors, this new barrage of listings also meant they had to work a lot harder. If, during the boom, agents had been able to close on a multimillion-dollar home without breaking a sweat, now they were courting buyers who might look at thirty houses before making a decision.

But now there’s an uptick in the air, Mathews says. The spec homes have sold, and the lack of speculative building is fueling sales. “Folks are making a landgrab,” she explains. “If you want a new house, there aren’t many left. That’s letting the owners of some of these lightly lived-in homes sell with more than one offer.” Across town, glittering high-rises are now welcoming moving vans (the Mathews-Nichols Group has sold a couple of seven-figure penthouses at One Arts Plaza). The big listings are back, like a $6.5 million French estate in Preston Hollow and a $16 million Frank Welch–designed home in Volk Estates. “The Park Cities and Preston Hollow were the last in Texas to go a little south and the first to come back,” Wilson tells me.

“We are a more conservative region by nature, and we’re not dependent on one industry,” Mathews adds later, citing luxury retail, oil and gas, and medicine. “Dallas has so many industries bringing in executives all the time. It keeps our high-end world fresh. For a while there were moratoriums on relocating. But now you are seeing them like crazy!”

Those executives arriving from Connecticut and California often assume they’ll be able to get twice the square footage for half as much in Dallas. People are shocked when they get here, Mathews says. “Often they discover that they will have to spend more, not less, because neighborhoods like Highland Park did not suffer the crash. It’s a very stable world here. I tell my clients, ‘I know that’s disappointing news on the come-in. But when you leave us, you’re going to be happy.’ ”

Mathews’s close dealings with relocating executives put her squarely in the tradition of Ebby Halliday, who has been selling luxury homes in North Texas since 1945. Halliday served on a city committee charged with wooing companies to the area and helped bring Dresser Industries to Dallas in 1950 before making her name as the glamorous (and ukelele-playing) grande dame of real estate. She counts Bush as a personal friend and sold Ross Perot his home. When I ask her how MLS Area 25 has weathered the slump, she smiles, then bellows, one word at a time: “There. Will. Always! Be. A. Highland. Park!”

Halliday has dominated Dallas real estate for more than six decades, acquiring other firms such as Ellen Terry Realtors and Dave Perry-Miller and Associates. Sitting in the library of her Palladian-style home, not far from the little white house in Preston Hollow that has served as her iconic headquarters during most of that run, she explains the basics. “Dallas is very social,” she says. “I’ve tried to make friends everywhere.” From the start, she donated heavily on the charity circuit, took calls from everyone she could, and became close friends with Stanley Marcus. (All gilded roads in Dallas lead back to Neiman Marcus.) A black belt in party-hopping is paramount. “Parties are where referrals take place,” she explains, particularly with those coveted executive relocations.

But it’s also about the personal touch. Halliday isn’t shy about saying women do it better; in fact she and others in Dallas have risen to the top partly because they’re women. “Some of us just innately render more service,” Halliday explains. She brightens at the mention of Mathews, calling her a formidable competitor. Of course, the centenarian agent can’t help but coyly mention that her realtors have had the highest number of million-dollar-plus sales in Dallas so far in 2011. (The MLS database backs this up.) “Erin’s customers never forget her,” she says. Halliday gets a mischievous grin and pulls out a copy of Ebby Halliday: The First Lady of Real Estate, by Michael Poss. “Erin’s got the right philosophy. I wonder when she will write her book.”

Mathews is perhaps the only other agent in Dallas who could, in fact, ascend to the queen realtor’s throne. She arrived from Oklahoma in 1976, when her now-ex-husband took a job in the city. The couple bought a cottage home on the west side of Highland Park, and Mathews, who had worked through school at a designer clothing boutique, soon landed at Neiman Marcus. After a stint in the corporate training department, Mathews’ sartorial eye was put to use in the buying office, where she spent a few years hauling around three-ring binders full of order forms and traveling extensively on market trips. Mathews tired of the grind, so she took a job in customer relations at the Main Street flagship. Her assignment: mingle with the store’s most important customers, lunch at the Zodiac Room, and forge relationships between bejeweled socialites and discreet personal shoppers.

She was a natural. “You have to be motivated by finding something special your customers didn’t even know they wanted,” she says, stating her luxury sales manifesto. “You have to love that.” Though she took some years off when her son, Travis, was born, by the time he turned ten, she was ready to sell again. The impetus for getting her real estate license came when a friend with young children put her house on the market. Mathews, who had helped a few other friends do the same, coached her from the sidelines.

As a Highland Park parent in those days, Mathews frequently volunteered for elaborate fund-raising efforts at Bradfield Elementary School. As luck would have it, the chair of the 1991 Dad’s Club was Robbie Briggs, the president of Briggs Freeman Sotheby’s International Realty; Mathews was the school carnival’s chair. By the following year, Mathews had gone to work for Briggs. Paying dues on the sixth floor of Neiman’s and logging hours on the kiddie charity circuit gave her the polish and the Rolodex for a career in high-end Dallas real estate. “I had contacts,” she says.

She still does. Mathews has clearly read Halliday’s book. She and Nichols appear in all the right places: store openings, fine-art receptions, charity balls. And like her predecessor, Mathews is tenacious. If a property is going to make D Magazine’s 100 Most Expensive Homes in Dallas list—a yearly event that Mathews’s understated clients rue as a “dark day”—she wants to have sold it. She tweets the latest price reductions, acquiesces to media requests, even makes a few waves. Two years ago she and Nichols defected from Briggs Freeman to the firm of Allie Beth Allman, walking with forty listings. “Briggs Freeman couldn’t make any more room for us,” says Mathews. After settling in, she and Nichols added four new hires. (Travis, who is now 29, is the managing director.)

When I get back in the car with Mathews, she takes me to the very first house she sold as a licensed realtor. We pass the city-mandated greenbelts of Greenway Parks, and her twin-turbo engine rumbles across Waneta Drive. Mathews taps the window again, pointing to a midsized fifties modern that had been owned by a Neiman Marcus customer. Mathews had taken her to lunch at the Zodiac Room.

In the thriving worlds of Park Cities, Preston Hollow, and One Arts Plaza, the successful realtor must wield not only a fully charged smartphone and a chic handbag but also the powers of a five-star hotel’s concierge. A Tuesday morning might include finding a client the right dog park and a good facialist. That afternoon could bring a tutorial on which streets are Ducati-friendly and the value of a heated toilet seat. Wednesday’s agenda: offering dating advice over breakfast tacos, then mailing a check to the charity of a former client who might be selling his house soon. Mathews even provides introductions for corporate chiefs and their wives and sets up playdates for their children. If she thinks you’ll hit it off with a new neighbor, she’ll casually set something up. She’ll tell you where to buy drapes and that your sprinkler is broken too. One client told me that after she and her husband relocated here, she texted Mathews for recommendations on the best manicurist, dry cleaners, decorator, pizza, coffee, and preschool. (She was stunned when Mathews got her daughter into the exclusive school.) Says Kip Tindell, the CEO of the Container Store, “I call Erin when I need an electrician.”

And that’s after the house has been bought or sold. When she’s putting a home on the market, a realtor like Mathews commandeers an army of minions for weeks on end, buffing, fluffing, decorating, redecorating, landscaping, and on and on. The prep work that goes into moving a multimillion-dollar house resembles the frenzied days before a Broadway premiere, an all-hands-on-deck, half-mad push to create a fleeting image of perfection. (And fleeting it is: the fresh paint, new drapes, and replanted shrubbery will often be immediately redone by the new owners.) Nothing is left to chance: Mathews synchs her BlackBerry to those of her staff, and she’ll always, always dispatch someone to light up a house before her arrival with a client.

A few days after our driving tour, I meet Mathews at a home in Preston Hollow. She is here to oversee a nine-person crew that includes her two assistants, Brittany Jones and Priscilla Garcia; four painters; two movers; and the stager, a 29-year-old named Brianna Wright who usually works with celebrity decorator Ann Schooler but is freelancing today. The owners of the house, who hope to put it on the market in two days, are nowhere to be seen, having ceded control to Mathews. They know that if buyers can’t see themselves living in the house—if the decor is too personal, too designed, too faux, too cramped—then there is no point in showing it.

As Mathews walks into the stone French home, her chiffon blouse brushes a cardboard box that’s filled with artificial ivy and headed out the door with a mover. Her face flashes a grimace. “Yep,” says Wright. “There’s eight boxes of that.” Soon it is all loaded into the mover’s van, followed by a few tables deemed too high. Leather-bound bar stools, one hundred pounds each, are banished to the garage. Grecian columns with string lights are dismantled. Sheets of Visqueen blur the leopard-print carpet. A few surviving thickets of ivy are spirited into the panic room.

And so it goes for the next seven hours. An oil pastoral scene is rehung; twenty yards of silk organza sheers are removed from a window; a dark-purple media room is brightened to a light beige and rebranded a playroom and den; a four-foot silk-velvet pouf is precipitously carried up the curved staircase; the dining table is given more demure chairs. After some consideration, the baby grand piano is granted a stay, since the owners’ son needs it for his lessons. But a polka-dot recliner in the girls’ room upstairs is not as lucky. Thankfully, though, a glittery “Every day is tiara day” placard is allowed to remain. Through it all, the family Yorkie squeals in the laundry room.

Mathews oversees every move, arms crossed, occasionally whispering to Wright. Once the frippery is quarantined, the two move outside and begin heaving iron patio furniture into a more home-tour-conducive arrangement. “Oh, my gosh, that looks better!” Erin coos falsetto, clapping her hands. “Ho-ly cow. Ding! Ding! Ding!”

At the end of the day, the staging will cost about $5,000. But Mathews has good taste—upon her return, the wife praises the realtor’s skinny Victoria Beckham pants and the de-ivying—and for the owners, who hope to sell the house for $1.5 million, the investment means the house will sit on the market for a shorter period. (It’s not uncommon for an offer to come in during the first few days.) As the photographer arrives to get shots for the brochure, Mathews whispers to me, “Someone once told me that if I can talk a builder into spending forty-thousand dollars on staging, then I’m a good salesperson.” She walks over to the coffee table and adjusts a potted white orchid.

Later that evening, we meet again. This time we’re in a condo on the second floor of a salmon-colored Highland Park high-rise, between Whole Foods and the home owned by art collector Kenny Goss and pop star George Michael. It’s not Versailles. Or even Versailles Avenue. But it’s where Mathews lives. “A well-known agent in our market found out I had bought in this building ,” Mathews says, kicking off her sandals. A candle flickers, filling the room with the scent of black currants and rose petals. “She goes, ‘Oh my gawwwd, Erin! I cannot believe you are living here. I thought you would at least be at One Arts Plaza.’ Again, there are no secrets in real estate.”

The muted two-bedroom space is filled with paintings by contemporary Texas artists, decorative quartz-crystal firewood, and a zebra-hide rug. Every day Mathews wakes at six a.m., drinks two cups of coffee, reads the entire Dallas Morning News, and gets dressed in her walk-in closet, choosing from among a dozen pairs of white jeans and a myriad of Chanel jewelry options, stacked in boxes with labels that read “garnet heart with gold chain” and “sea pearls gold.” By eight she’s at the Allman offices, where she shares her ten-by-ten-foot space with Jones and Garcia, who sit less than an arm’s reach away in discounted office chairs. (Says Travis about the humble digs, “Clients don’t see her office.”)

The understatement is by design. While Mathews travels in gilded circles—power lunches at Al Biernat’s, seats at the Crystal Charity Ball fashion show—she is conscious of how quickly it could all disappear. She’s seen colleagues suffer from the feast-or-famine cycles that can plague high-end realtors. “Residential real estate is a lifestyle,” Mathews says, sinking into the deep sherbet-colored sofa. “I live in a commission-based world. You don’t know what’s going to happen. If I don’t work, I don’t make money.”

So work she does—relentlessly. Twelve-hour days are not uncommon. “I expect good customer service as a customer, and I expect to give it as a service provider,” Mathews concludes. She remembers a furniture ad from the community newspaper Park Cities People a few years ago. “It said they were looking for someone with a servant’s heart. I thought, ‘Well, that’s it, isn’t it?’ ”

That is it. After all the texting, the hours logged in the Mercedes, the days spent climbing more than forty flights of stairs, and the many Chanel bracelets she keeps breaking on stubborn key boxes, Mathews’s clients aren’t immediately her friends. There might be dinners at some point, she says, but she always waits for the client to make the first move.

“I know my place,” Mathews says, making a slow karate chop on the arm of her sofa. Even after selling five and six homes to many of Dallas’s wealthiest, after selling some of the same $5 million houses three or four times, Mathews is unashamedly contract labor. “I am not one of them. I am the worker bee. I am not their equal. I perform a service. Just like their attorney or their accountant.”

Her phone vibrates. “I know where I stand in the universe.”