In 1971 Robert P McCulloch bought London Bridge and shipped it to a small desert town. But, as our writer finds, the pre-Victorian masterpiece is very much at home on the Colorado River in the heart of Mojave County

Lake Havasu City lies by the Colorado River on a 45-mile stretch of clear water amid the desert peaks of western Arizona. It is about 150 miles from Las Vegas and a seven-hour drive from Los Angeles. In summer the temperature has been known to reach 50C. The landscape is characterised by arid expanses of loamy sand, bare red rock and eroded sediment, while the local flora – cat claws, bursage and mesquite – pokes out of the dusty ground like bristles on a hog. A more unlikely setting for a 19th-century British architectural landmark can't really be imagined. And yet John Rennie's London Bridge has called Lake Havasu City home since 1971, the year of my own birth. Captivated since childhood by the story of its transplantation, I vowed to visit it.

Preparing for the trip, I was excited to read about the so-called "English Village", a mini London theme park beside the bridge. And on arriving at its south bank, bridge seekers are greeted by silver City of London griffins, a diminutive Trafalgar Square fountain attended by Lilliputian Landseer lions and a red phone box. Sadly, a British pub, once famed for serving imported Watneys Red Barrel in tankards, was boarded up and awaiting demolition, while a Routemaster bus that had long stood at the foot of the bridge, serving as an ice cream van, has been banished to a dusty breakers' yard.

If the English Village was severely depleted, London Bridge, by contrast, looked surprisingly well. Studying old postcards, it had always appeared rather dowdy to me. But freed from the confines of a smoky hugger-mugger cityscape, Rennie's neoclassical crossing seemed regal, majestic even, under a blazing midday Arizona sun. Compellingly, the stonework still bears smudges of soot and patches of graffiti – some legibly dating from the time of the Blitz. All of which rather poignantly attests to the bridge's distinguished service in the smoke. And in such intense heat, there's pleasing surreality to spying a manufacturer's casting mark at the base of a lamp that reads: "T Potter & Sons, South Moulton St W".

Model town: Trafalgar Square fountain in the English Village theme park. Photograph: Travis Elborough for the Observer

The bridge's fantastical journey from rain-drenched Southwark to dust-dry Mojave County began in 1967, when the Corporation of London put it up for sale. Fashioned for posterity in 130,000 tons of granite in 1831, the span was calculated to be sinking at a rate of an ⅛th of an inch a year by the early 1960s. Its eventual purchasers (and also the founding fathers of Lake Havasu City), Robert P McCulloch and CV Wood, are immortalised in a statue at the northern end of the bridge. McCulloch was a flamboyant millionaire oil baron and chainsaw magnate who hatched a scheme to build a new city out here in the desert in 1963. The actual idea of buying London Bridge at a cost of $2,460,000 (£1,029,400 10s 4½d old money) came from Wood, his business partner. Previously the planner behind Disneyland, Wood felt it would put the place on the map. He was proved right. Today, 50 years after it was established, the city has more than 53,000 residents. Those numbers are bolstered every winter with the arrival of seasonal retirees known as "snow birds". In turn, each spring they are replaced by thousands of college students who flock here to party on the lake. Adverts for pasties – those little fez hats for nipples worn by sorority girls – are displayed outside waterfront gift shops. As are posters for the horror movie Piranha 3D, which was filmed here in 2009.

When it comes to the tale, cherished by London cab drivers, that the Americans thought they were buying Tower Bridge, locals are dismissive. At the Lake Havasu City Visitor Bureau, Jan Kassies insists the story hailed from McCulloch himself. "He made that up. He was a jokester. He did it just to get the media attention." A Dutch retiree who emigrated here a decade ago, Kassies stresses that the lake itself was their biggest attraction. Most visitors come here to fish, swim or go jet skiing or speed-boating.

Over at the Lake Havasu Museum of History on London Bridge Road (its entrance guarded by a life-size model of a Beefeater), two of the town's oldest residents, Lyle and Stellene Matzdorff, are proud to call themselves pioneers, and remember the hardships of the early days. "That first year," Lyle recalls, "there was nothing here, and I mean nothing. Most people were living in tents. The nearest store was a 60-mile round drive." It was touch and go for a while. "But then McCulloch bought London Bridge and people started saying: 'The town is going to make it; you don't buy London Bridge for nothing.' Things picked up after that."

If London Bridge secured Lake Havasu City's future back then, it's perhaps inevitable that today it has settled into being an accepted, and slightly unremarkable, part of the furniture. Instead, all the excitement that evening at the Desert Martini bar – a Havasu institution – was being generated by a local festival, the annual lighting of Cupcake Mountain. This autumn ritual involves the illumination of a mountain on the nearby Whipple Range whose crown is periodically frosted with snow. It is an event, as one drinker puts it, "that folks in these parts all look forward to".

Newcomers and visitors, however, tend to get confused by it. "The police," Kassies tells me, "get a lot of calls about UFOs." He smiles and then adds impishly: "Well, we assume it's Cupcake Mountain, but it could be UFOs. You have to get used to seeing strange things around here – I mean, we are the home of London Bridge."

London Bridge in America: The Tall Story of a Transatlantic Crossing (£14.99, Jonathan Cape) is published on 7 February. To order a copy for £10.39 with free UK p&p, click on the link above or call 0330 333 6846

Essentials



British Airways (britishairways.com) flies London to Las Vegas from £574 return. Lake Havasu City is a 2.5-hour drive from Las Vegas. Rooms at the London Bridge Resort Hotel (londonbridgeresort.com) cost from $95. For more information, visit golakehavasu.com