The noisy, dusty camp sprang up in July with 20 residents and now numbers 200 people, including several children, growing as this region east of Los Angeles has been hit by the U.S. housing crisis.
The unraveling of the region known as the Inland Empire reads like a 21st century version of "The Grapes of Wrath," John Steinbeck's novel about families driven from their lands by the Great Depression.
As more families throw in the towel and head to foreclosure here and across the nation, the social costs of collapse are adding up in the form of higher rates of homelessness, crime and even disease.
While no current residents claim to be victims of foreclosure, all agree that tent city is a symptom of the wider economic downturn. And it's just a matter of time before foreclosed families end up at tent city, local housing experts say.
"They don't hit the streets immediately," said activist Jane Mercer. Most families can find transitional housing in a motel or with friends before turning to charity or the streets. "They only hit tent city when they really bottom out."
Steve, 50, who declined to give his last name, moved to tent city four months ago. He gets social security payments, but cannot work and said rents are too high.
"House prices are going down, but the rentals are sky-high," said Steve. "If it wasn't for here, I wouldn't have a place to go."
Nationally, foreclosures are at an all-time high. Filings are up nearly 100 percent from a year ago, according to the data firm RealtyTrac. Officials say that as many as half a million people could lose their homes as adjustable mortgage rates rise over the next two years.
California ranks second in the nation for foreclosure filings -- one per 88 households last quarter. Within California, San Bernardino county in the Inland Empire is worse -- one filing for every 43 households, according to RealtyTrac.
Maryanne Hernandez bought her dream house in San Bernardino in 2003 and now risks losing it after falling four months behind on mortgage payments.
"It's not just us. It's all over," said Hernandez, who lives in a neighborhood where most families are struggling to meet payments and many have lost their homes.
She has noticed an increase in crime since the foreclosures started. Her house was robbed, her kids' bikes were stolen and she worries about what type of message empty houses send.
The pattern is cropping up in communities across the country, like Cleveland, Ohio, where Mark Wiseman, director of the Cuyahoga County Foreclosure Prevention Program, said there are entire blocks of homes in Cleveland where 60 or 70 percent of houses are boarded up.
"I don't think there are enough police to go after criminals holed up in those houses, squatting or doing drug deals or whatever," Wiseman said.
"And it's not just a problem of a neighborhood filled with people squatting in the vacant houses, it's the people left behind, who have to worry about people taking siding off your home or breaking into your house while you're sleeping."
Health risks are also on the rise. All those empty swimming pools in California's Inland Empire have become breeding grounds for mosquitoes, which can transmit the sometimes deadly West Nile virus, Riverside County officials say.
But it is not just homeowners who are hit by the foreclosure wave. People who rent now find themselves in a tighter, more expensive market as demand rises from families who lost homes, said Jean Beil, senior vice president for programs and services at Catholic Charities USA.
"Folks who would have been in a house before are now in an apartment and folks that would have been in an apartment, now can't afford it," said Beil. "It has a trickle-down effect."
For cities, foreclosures can trigger a range of short-term costs, like added policing, inspection and code enforcement. These expenses can be significant, said Lt. Scott Patterson with the San Bernardino Police Department, but the larger concern is that vacant properties lower home values and in the long-run, decrease tax revenues.
And it all comes at a time when municipalities are ill-equipped to respond. High foreclosure rates and declining home values are sapping property tax revenues, a key source of local funding to tackle such problems.
Earlier this month, U.S. President George W. Bush rolled out a plan to slow foreclosures by freezing the interest rates on some loans. But for many in these parts, the intervention is too little and too late.
Ken Sawa, CEO of Catholic Charities in San Bernardino and Riverside counties, said his organization is overwhelmed and ill-equipped to handle the volume of people seeking help.
"We feel helpless," said Sawa. "Obviously, it's a local problem because it's in our backyard, but the solution is not local."