"They're from all walks of life and all parts of the country," says Phyllis Seal. She and her husband, Larry, are volunteer managers for the La Posa LTVA, a cakewalk job for two retirees tasked with little more than issuing camping permits and fielding complaints.

They're sitting under the shade of their RV, visiting with BLM Ranger Clyde Praast and looking out on the RV city that spreads around them. Praast says they also get a handful of tents during the season, some sleeping bags in station wagons, even a teepee or two. "We see the whole range -- from a hundred bucks to a million bucks."

Praast says the RV crowds have been growing in recent years, despite what some describe as a decline in attendance at Quartzsite's shows and swap meets. Despite their proximity, the swap-meet culture inside Quartzsite proper and the boondocking ethic of the LTVA campers represent two distinct facets of this place and of the economic recession. The low-cost lifestyle of the LTVA has likely become even more appealing during these tough times: With the crash of the housing market, a half-year's rent of $180 is tough to beat. The declining attendance at the swap meets and shows could just be a symptom of the widespread pull-back in discretionary spending. A handful of major recreational vehicle manufacturers have also gone out of business in recent years, chopping what was a nearly $15 billion industry in 2006 down by almost a third. There's less to sell, and fewer to buy what's left. But for many in the LTVA, the shows and swap meets are a minor diversion, off in the distance. Such things are not the reason they come to this desert.

"There's tons of people like me who don't come out here for the event. We come out here for the camping, the peace and quiet," says Ron Jones, a middle-aged Oregonian who spends more of his time away from home than in it. He's smoking a cigar as he washes his dishes. He's got a four-basin dishwashing setup on a makeshift table outside his camp, which consists of a 12-foot trailer and a screened patio area. It's neat, compact and sturdy enough to stay that way for months.

He's been here since before Thanksgiving and won't leave until April. He looks like someone who knows how to get by in the desert, with his black cowboy boots, blue jeans, Western-style button-up and a mustache that could steer a Harley. His hat proclaims "Shit Happens" in a way that simultaneously acknowledges the fact and strives to find a solution. He lives alone, but he's not the solitary type. Besides, he says, he's never lonely here.

"I've got more friends out here than I do at home," says Jones.

He's been coming out to La Posa for about eight years, and he camps in just about the same spot every year. Down the way is his friend, Jim Nicholson, who always camps nearby. They come for the weather and the slower pace of life. And even though they've got their separate places and every piece of equipment they need to survive on their own, they can't help but revel in the community around them.

"Everybody's friendly. If they're not, usually they don't like it around here," says Jones. "If you've got problems, they'll help you. You don't have to ask. They'll just show up."

An open hood on an RV is like an invitation to a party, according to Jones. Men will wander over from far-off campsites to see what the problem is and whether they can help. Some might say it's because there's not much else to do out here. Then again, living in the desert creates a common bond –– an awareness of the possibility for serious trouble, even from behind the wheel of a luxury motorhome.

"If you're dependent on people, you tend to be more supportive when they need help," says Jones. He says the community life is much stronger here than he's ever known anywhere else.

The La Posa Long Term Visitor Area is the kind of neighborhood where every front door is unlocked, though "front door" is a flexible term. The living rooms here are outside, and it's nearly impossible to walk past one without receiving a wave or hearing a hello. Campfires dot the horizon after nightfall, and the gentle hum of thousands of power generators underlies the desert's evening soundscape like the dull background noise of city traffic.

For many of the campers passing their winters in the calm of the desert, La Posa's not too far off from a regular city, both in the social sense and the physical sense.

To do research for his dissertation, Simpson stayed out in Quartzsite for a few weeks in January 2008 and again in January 2010. At one point, he took a short flight to get an aerial view of the place, and he says the impromptu city's form was just as varied as any permanent place.

"There are different densities and different kinds of arrangements," says Simpson, who looks at the RV community from an architectural and urban perspective. "You see courtyards set up where they park to make an interior space. They'll have larger gatherings where there are up to 30 or 40 vehicles in a circle, or you see more of a suburban arrangement where everyone is equidistant and turned away from each other. It's really a mixed situation."

And the situation is just as harmoniously disjointed in terms of its social structure. But even for a community that forms, disappears, and then re-forms year after year, there's a surprising cohesion. Members often keep in touch, and many even visit each other outside the season, beyond the borders of the LTVA.

"We made a decision to buy a motorhome, and we got all these friends along with it," says Kay Green Losh, who comes out from Texas annually with her husband and their 1983 Blue Bird Wanderlodge. "The only thing that's bad about it is my friends are scattered all over the U.S."

For this instant, fleeting city of RVs, that reality is both a challenge and a testament to its residents' self-sufficiency -- qualities often missing in modern-day cities.

But as environmental concerns and sustainability issues become more important, those qualities are emerging again, even in the big city. In the immobile world of cities and suburbs, backyard gardens put salads on tables, rain-collection barrels harvest water for household use, and solar panels detach homes and buildings from the energy grid. In a mobile home community without electrical hookups, everything is off the grid. It may not exactly line up with the ethos of the sustainability movement -- after all, the food the RVers eat has to come from somewhere, and there's no denying that these things burn up fossil fuels at alarming rates. Still, the decentralized nature of mobile homes gives them a sort of pilot-project quality. From local energy harvesting to resource conservation to community building, the mobile world may offer some lessons for its nailed-down rivals. If it can work on the road, or out in the middle of the desert, maybe it can work in an actual city.

"Being in the boondocks, you have to be really careful about how much you consume. You can't really use up a lot of water, because then you have to move and get more. And if your tanks get full, same problem. So you don't take a shower every day. And when you do, it's two minutes long," says Varnelis.

Even within Quartzsite proper -- a midpoint between the traditional city and the temporary desert metropolis -- the RV ethic has seeped into the town's bloodstream. Entire sections of the town are effectively shut off like a light switch when the crowds and vendors leave. Swap-meet grounds sit silent and empty. But when the crowds return, that emptiness surges back to life.

Now, however, it's getting on springtime, and Quartzsite's temperatures are beginning to climb. The swap-meet hawkers have packed up their trinkets and tents, and the wandering shoppers have taken their discount merchandise and hit the road, headed back towards home or on to another beckoning deal. As the population dwindles to about 3,500, the metropolis of a million-plus snowbirds is little more than a memory.

The RV city has vanished, scattered like seed pods on the wind, dispersed in thousands of homes, trailers and RVs across the continent. The community is now in hibernation, but come next winter, it will be wide awake and buzzing again.

Nate Berg is a freelance writer working on a book about city-like places. He lives in Los Angeles and camped at  the La Posa Long Term Visitor Area in a tent. He felt out of place, but very welcome.