TECATE, MEXICO — The air is already laced with diesel fumes as the conductor shouts, "All aboard!" The engineer sounds the whistle, and the locomotive lurches forward.
Squeals of delight emanate from the passenger cars. This train ride is a first for many of the children. The adults share their excitement because they are setting off on a unique international adventure.
One or two Saturdays a month, nearly 250 passengers -- kids and grown-ups -- climb aboard the 1930s-era passenger cars in Campo in eastern San Diego County for the one-hour trip to Tecate, a town that provides a tranquil alternative to bustling and crime-ridden Tijuana, about 30 miles west.
Volunteers from the Pacific Southwest Railway Museum, which runs the trips, have restored the cars to their original appearance. Until they were retired in the mid-1980s, the cars trundled across northern New Jersey for more than five decades, carrying New York City commuters.
But now there's not a single suit-wearing, briefcase-carrying businessman in sight, and no one is forced to stand. (The original rattan was, thankfully, replaced with vinyl-covered foam about 30 years ago.)
The engine chugs along at 15 mph. Train aficionados, including Bob and Sandy Schussler, share the history of this stretch of track, which until the mid-1950s carried passengers traveling east from the coast.
"We are preserving the legacy of railroading in Southern California," says Bob Schussler, a former Marine who, with his wife, has spent more than a decade as an active volunteer with the museum. "I don't ever want to hear a little kid ask his father, 'Daddy, what's a train?' "
He tells visitors that the international railroad was built in the early 1900s to connect San Diego with the crop-rich Imperial Valley. Trains leaving San Diego traveled south into Tijuana before turning east. They remained on Mexican soil -- which was both flatter and cheaper than the land a few miles to the north in California -- until they were about 10 miles east of Tecate. Today's excursion trains travel on the same tracks that were laid nearly a century ago.
The point at which the tracks cross the international border, inside a 600-foot-long tunnel, is one of the highlights of this train trip.
"The Mexican border is about 20 feet from the far end," Bob Schussler says.
"The border is delineated by a white painted stripe," he continues, while shining the beam from his powerful spotlight along the rock wall.
"There!" exclaim dozens of passengers in unison.
Round-trip tickets cost $43 for adults and $23 for children. The trips often sell out weeks in advance, especially during the milder spring and fall months, when extra excursions are added to meet the increased demand. Through next May, American citizens will need only a driver's license or other government-issued photo ID to make the journey. As of June 1, all travelers will need to present passports or passport cards.
Within minutes of leaving the tunnel, the desert scrub begins to be replaced by homes on the dusty outskirts of Tecate. Children scamper out of the ramshackle dwellings and run alongside the tracks, exchanging waves with the passengers.
As the whistle announces the train's arrival at several busy crossings, motorists wave from their stopped vehicles. And, as the engineer applies the brakes outside the depot, even the policia -- rifles slung over their shoulders -- are waving hello.
The station is dwarfed by the huge brewery behind it, which bears the town's name: Tecate.
Andres Contreras Camargo holds a large placard that reads, "Brewery guided tours," and as the passengers alight, he invites them to accompany him inside. Dozens oblige. Many already know that there's free post-tour cerveza in the adjoining beer garden.
Contreras, a university student who works part-time as a marketing intern, begins by explaining that the town was here well before the brewery. It was incorporated in 1892, but the brewery didn't open until 1944. Photos depict the early history of both.
During the 45-minute tour, guests see the huge copper kettles in which beer was first brewed. (They've been replaced by equally enormous stainless steel vats.) There's also a visit to the assembly line, where the still-warm and bubbly beer is pumped into 750 bottles a minute.
In the beer garden, visitors get a ticket good for one free beer. The guests can choose among the several brands made here, including Dos Equis, Sol and of course, Tecate.
If hunger is an issue, visitors, using a map distributed onboard by the train's crew, can make the five-minute walk to the town plaza, where the aromas of onions, peppers and garlic waft from more than a dozen restaurants on the streets around the square, known as Parque Manuel Hidalgo.
Locals flock to Los Amigos, a hole-in-the-wall that serves tasty and inexpensive carnitas.