The project's visionaries see Superstition Vistas as a sort of buffer set against the typical Arizona sprawl. Today, it looks more like a detached outlier, not unlike the leapfrog development it was supposed to help Phoenix avoid. If the land were developed today, its residents would face a long, energy-intensive drive to the city's center. Assuming they had a reason to go there, given the dwindling supply of jobs these days.

Still, Gammage and others believe growth will resume, at least to some extent, probably stabilizing at what used to be the "normal Arizona growth level" before the most recent boom where the population of Maricopa County -- which includes Phoenix and its eastern suburbs -- was increasing by 100,000 people per year. Now more than ever, says Gammage, good planning is important for Superstition Vistas.

"The risk, with housing prices coming down and land prices coming down," he says, "is that the tendency when demand returns is to go back to business as usual. And there will be pressure on the State Land Department, which right now can't sell anything, to try to sell stuff." Winkleman, the land commissioner, echoes the sentiment, saying now is "not the time to lose our focus" on the Superstition Vistas model.

Sandy Bahr of the Sierra Club agrees that growth will probably return, maybe even as a stampede to develop the fringes of the city. Yet she sees opportunity in the downturn: a chance, perhaps, to stop the likes of Superstition Vistas from ever happening.

"I think it (the downturn) buys us time in the short term and may give us an opportunity to pull together a measure that would help to conserve them (state lands)," says Bahr. "It also buys us time to try and shift some policies that would require that sprawl development really pay for itself. That would make this mega-development far from the city centers look a lot less attractive."

The Morrison Institute report, The Treasure of the Superstitions, lays out three possible scenarios for the future of Superstition Vistas. Each imagines a livable, well-planned, green collection of new cities. In "Thinking Big," urban areas are focused around pre-built infrastructure. In "Simple Green," homes are powered by the sun, residents water their cacti gardens with effluent, streets and houses are made from material that reduces the heat-island effect that has turned Phoenix's once-cool evenings into concrete ovens. And "Superstitionville" is a new urbanist's dream, with "true downtown" areas in each subdivision and no fences allowed.

It's an appealing vision. As Utah planner Robert Grow put it: "Planners would think they'd died and gone to heaven with the opportunity to plan something like (Superstition Vistas), and I'm one of them." Indeed, this huge parcel of land could be a smart-growth testing ground. Imagine a well-planned, sustainable city arising on the edge of Phoenix, the very metropolis that epitomizes all that's wrong with exurban sprawl. It could provide a role model for the rest of the Sun Corridor. "This is a test case and a unique opportunity," says Winkleman. "If we can do something like this, then we will be successful. If we don't, then we will have failed."

But this is clearly a large-stakes gamble on a vast area of land, especially considering that smaller test pieces already exist. The Phoenix metro area contains more than 300,000 acres of vacant, developable state trust land -- not including Superstition Vistas -- along with some 120,000 acres of available private land. Much of that land is already next to roads, schools and waterlines, and some of it is near the urban core, which is where people tend to be moving in these days of suburban blight and higher gas prices.

There is one scenario that is conspicuously absent from all the promoters' reports: Simply leaving the land as it is. There is virtually no cost to the state to leave the land undeveloped and there is no requirement in state statute that the land must be sold at any particular time. The plans do include preserving 25,000 acres of desert highlands next to the Superstition Wilderness Area, but the remaining 150,000 acres of lowland desert is generally viewed as a sacrifice zone. The land's value to the visionaries, it seems, lies entirely in its potential as a smart-growth-planning playground.

"From a conservationist's point of view, it has no environmentally sensitive things that need to be preserved for future generations," says Backus, the early proponent for planning Superstition Vistas. "If you're going to build houses, let's build houses there instead of up against the mountainside. It's not a wasteland, but it is just desert scrub."

Biologist Ken Sweat and other conservationists have a starkly different view. At the moment, Superstition Vistas is still just a vast, undeveloped section of desert, covered by cactus and threaded by washes, their sandy bottoms etched with the tracks of lizards and snakes and javelinas. To give this up in the name of sustainability seems, quite simply, unsustainable.

"If our civilization is to ever embrace sustainability, it would seem prudent to begin now," says Sweat. And the best way to do so, he says, is to "preserve what natural spaces are left, and plan better to use the landscapes we have transformed in the past to help meet the needs of the future."

This coverage is supported by contributors to the High Country News Enterprise Journalism Fund.