See Correction & Amplification below.

When she hit 60, Sarah Coleman thought she was done raising children. But today she is among the millions of Americans left to fill the void for family members gone to jail.

Now 66 years old, Ms. Coleman has three youngsters at home -- ages 5, 3 and 1. She doesn't know the whereabouts of her granddaughter, who is their mother. As for the children's fathers, they have both been in trouble with the law. One is in prison serving a 10-year term for second-degree murder. The other has been in and out of jail on drug charges.

"I didn't intend to raise my great-grandkids," says Ms. Coleman, who relies on supplies of diapers and baby wipes from a local social-services center. "There are so many things I can't do for them because of money, but I have to try."

Here in South Mountain, a district in south Phoenix, more than 3,800 residents are displaced, serving time in prison or the county jail. For every 100 adults, 6.1 are behind bars. That's more than five times the national average of 1.09 per 100, according to a report by the Pew Center, a nonpartisan research group. Arizona has the fastest-growing prison population of the Western states, having increased 5.3% in 2007 to more than 38,000.

Behind those figures are many hidden, related costs -- financial burdens that communities are often left to manage. For every person who goes to jail, businesses lose either a potential employee or customer. Inmates' children often depend on extended families, rather than a parent, to raise them. With only so many government resources to go around, churches, volunteer programs and other groups must often step in to help.

In one nine-block stretch of central South Mountain, nearly 500 out of 16,000 residents are in the state system either as prisoners or as probationers who return regularly to jail. Prison costs associated with this nine-block area amount to roughly $11 million annually, according to an estimate from the Justice Mapping Center, a New York organization that examines crime patterns.

But the state spends more than half that amount -- an additional $6.5 million -- on social programs for the residents who remain. In that nine-block span, 2,000 people receive cash payments under the federal government's 

Temporary Assistance for Needy Families program. Nearly 5,000 are on food stamps. Almost one-third of the residents live below the poverty level. The total cost of prison and social services combined: approximately $2 million per block.

South Mountain may seem like just another desert town, yet its demographics are complicated. While a crackdown on crime has produced a high incarceration rate, it has also made the area attractive to new pockets of middle-class residents. Shopping malls, restaurants and grocery stores dot the area; there's a Target and a Wal-Mart. Gated communities and golf courses abound.

Most notable is what's missing: men of a certain age. "It's sad but we have men who are over 35 and we have young people under 17," says Faye Gray, a 71-year-old neighborhood activist. "The ones in between are missing." She quickly recites a half-dozen names, all men serving lengthy drug sentences -- people she watched grow up.

South Mountain's residents are mainly Hispanic and African-American. According to various studies, those two groups are the most overrepresented in the criminal-justice system. The Pew study released earlier this year showed the overall incarceration rate for all whites was one person per 245 adults, compared with one in 41 for blacks and one in 96 for Hispanics.

Arizona officials are worried about the $900 million the state spends annually on corrections. In an attempt to reverse the trend, the Department of Corrections has created several programs to give inmates tools to live successfully on the outside. Many convicts, for instance, can't read, so literacy is a focal point. One project seeks to identify job prospects for inmates, and offers classes in automotive, construction and catering fields. More than an effort to counter recidivism, such initiatives are meant to ease the burden of social-service providers -- programs already helping inmates' families.

The interplay of crime, poverty and race has long been a topic of study among criminologists and sociologists. Whether poverty creates crime or crime begets poverty is "an impossible question" to answer simply, says David Kennedy, director of crime prevention and control at John Jay College of Criminal Justice in New York.

The longterm decline of today's minority areas -- from drug epidemics and white suburban flight to a gradual rise in prison populations and budgets -- has taken a toll, says Mr. Kennedy. "These things play off each other," he says. "It's not arguable any longer that some of the things we're doing to fight crime are promoting crime and exacerbating poverty."

Here in South Mountain, the impact of prison is unavoidable. At the Southminster Presbyterian Church in South Mountain, children attend Head Start classes. Among other things, the federal program provides grants to help preschoolers develop reading and math skills. It handles about 160 children, says Doris Lewis, the administrator. Three-quarters of them, "if not more," come from single-family homes, she estimates. In many of those cases, the missing parent is in jail.

"The thing you notice with the children is they will mimic the effects of the prison system," she says. "They will play as if they are arresting another individual." Some even know the Miranda rights that officers relay to suspects during their arrests.

Providing Social Services

Assisting people like Ms. Coleman, the great-grandmother, are nonprofits such as the Black Center. It, along with the Keys Community Center, offers some of the most comprehensive social services for South Mountain residents. 

Supported by government funding and private donations, it has paid Ms. Coleman's utility bills and helped her obtain medical care. Each week, the center gives her a "food basket" worth about $50 that includes breakfast cereals, diapers, canned juices and other staples.

Right now, the family lives on Ms. Coleman's pension and Social Security of about $995 a month. "I pay $546 a month for the house and I take the rest of the money to pay the utility bill or other things and I don't have anything left," she says.

Mary Black, the Black Center director and founder, is trying to find a donor who will pay $400 for dentures for Ms. Coleman.

Emily Jenkins, director of a project funded by Gov. Janet Napolitano to measure the impact of imprisonment on families, says the state has approximately 95,669 children with incarcerated parents. An additional 80,398 have parents on probation.

This matters because children of jailed parents are five to seven times more likely themselves to end up behind bars, according to federal statistics. A third of the Arizona prison population had at least one parent locked up during childhood, according to the state project's research.

Darlene Marquez's daughter, Essence, was nearly 2 and her brother Xavier 3 weeks old when their father went to jail. The arrest left Essence frightened of police.

"She was in the back seat of the car one time and a police car pulled up next to us," recalls Ms. Marquez, 26. "She started screaming and saying, 'The cops, the cops. They take mommies and daddies to jail.' I couldn't tell her then that they only take bad people to jail, because her daddy was in jail."

Only recently, under coaxing from her mom, has the girl come to understand that police are there to help.

Her father served four years for intimidation and assault and returned home for about nine months before new violations sent him back. Since then, contact has been intermittent, says Ms. Marquez, who believes he is now out of prison.

Her son, now 6, recently began telling friends his dad is dead. In the past, he told stories about fishing trips they'd taken and movies they'd seen -- none of them true. "It's sad. I had to set him straight," says Ms. Marquez.

After quitting high school, Ms. Marquez earned her graduate equivalency diploma, or GED, and then trained as a medical assistant. Now she works in the clerk of court's office for Maricopa County and relies on the YMCA and Big Brothers Big Sisters to help with the children. Ms. Marquez says she now shelters her children, even avoiding family members and places from her own childhood she considers bad influences. "I want them to see the right way," she says.

North of Ms. Marquez's home in a neighboring zip code, hundreds of destitute families filter into the cavernous cafeteria of the Society of St. Vincent de Paul. 

About 400 meals are served here each day and thousands of children annually receive treatment at its emergency dental clinic. A mile away, another of the society's five local centers provides daily breakfast and lunches to more than a thousand of the city's homeless. In 2007, the Roman Catholic center had served 589,801 during the first five months of the year. This year the figure was up to 639,051 for the same period.

Stephen Zabilski, the centers' executive director, estimates that 50% of the people the center serves are former felons, many from South Mountain and other high-incarceration areas in Phoenix.

The people who rely on such programs have little margin for financial setbacks. Mr. Zabilski and others have seen even minor problems, like a flat tire, send families into the street. (Car trouble often means arriving late to work, which in turn can be grounds for firing.)

Gine Douh, 44, works the cash register at his Broadway Food & Meat Market. He says shoppers are mainly older nowadays, with few young adults coming in. He has a longtime worker he trusts, which allows him to leave the store occasionally. Still, he's reluctant to hire others in case they've had previous run-ins with customers.

Overall, though, Mr. Douh says the emphasis on law enforcement has created a neighborhood that's "more quiet. It's nice."
'Extinct'

Down the road, two of the three barber chairs in Watson's Barber Shop are empty. Dennis Watson, the owner, is alone snipping and clipping as the line of waiting customers grows. He has tried to mentor younger barbers in recent years but lost them to jail or prison.

"I have a lot of real young customers whose mommas bring them in and I have customers that are older," says the 47-year-old barber. "The young black men in this area are extinct."

In 2005 he had three employees and a larger number of younger customers. In each case, the barbers vanished. He'd hear through word of mouth that they'd been arrested. One got in trouble for violating conditions of his release, he says. Others, he says, were "doing wrong" and committing new crimes.

One man was assaulted in front of him, inside the shop, Mr. Watson recalls. The gunman walked in wearing a mask. Mr. Watson thought it was a robbery until the gunman hit one of the barbers on the head, then fled. "Somebody pistol whips you in broad daylight in a barbershop full of people, it's pretty clear you're involved in bad things," he says.

Unlike Mr. Douh, Mr. Watson does not have a trusted employee. When he leaves, even for lunch, he has to lock up shop. Over the course of a recent day he tended two dozen customers. Only two were younger than 30.

"What these young people don't understand is they are dooming their kids and their families," Mr. Watson says. "When you mess up, you're taking other people with you."

Correction & Amplification
The Black Family and Child Services of Arizona is a nonprofit organization that helps poor families. It was incorrectly referred to as the Black Center.