SAN JOSE — Ruth Greathouse is a diminutive woman with a quick smile and gentle manner. But there is steel in her words. The retired middle school teacher promises that if she and her husband are forced from the Winchester Ranch Mobile Home Community, it won’t be without a fight.

“They’re going to have to take me out in handcuffs,” said Greathouse, 69.

The 150 residents of Winchester Ranch mostly are seniors, some in their 90s, and they have been dismayed to learn that their 16-acre park in West San Jose is a prime piece of real estate sitting squarely at the intersection of the increasingly heated debate in Silicon Valley over development and affordable housing. The park’s owners are negotiating to sell the land beneath the 111 mobile homes to make way for a project that’s likely to include luxury-style condos attractive to well-paid tech professionals.

For residents largely on fixed incomes, who have banded together to save their close-knit park, the prospect of being uprooted from the places where they want to spend their final years around friends is deeply personal.

However, the broader issue for San Jose is whether Winchester Ranch could herald the start of a trend of converting mobile home parks into upscale residential, retail and office developments — making the South Bay’s affordable housing crisis even worse.

San Jose has the most mobile-home parks in the state, with 58 containing about 10,800 spaces. They are an important, under-the-radar stock of relatively inexpensive housing for seniors, the disabled and the working poor.

The land those parks sit on, though, can be appealing to developers eager to build high-density, high-end housing. James Zahradka, a Law Foundation of Silicon Valley senior attorney, argues that the city — which would need to approve any land-use change — needs to strike a balance between managing Silicon Valley’s current building boom and protecting the community’s most vulnerable residents.

“It shouldn’t be just about making all the money you can and forgetting about the effect on others,” said Zahradka, who represents the Winchester Ranch residents. “We’ve heard from the city that other developers have asked about the (conversion) process. So depending how it turns out here, this park could be the start of a slippery slope or the thumb in the dike that stops it.”

For residents such as Joan Randall, a 66-year-old Lutheran pastor, Winchester Ranch is just home. She talks about her yellow kitchen and how much she looks forward to coming home from work each night. Like others, she doesn’t know where she would go if the park were sold.

“This is taking hope away and putting our retirement in limbo,” she said. “When you’re in your last years, you want to be in a place where people care for you and you have real neighbors. It’s just not right that this could happen. I think San Jose has a bigger heart than this.”

Winchester Ranch, situated next to Interstate 280, is tucked behind the famed Winchester Mystery House. Once a part of heiress Sarah Winchester’s ranch, it’s now an oasis of mature trees, shrubs and flower beds situated around well-tended manufactured homes that bear little resemblance to stereotypical “double-wides.”

Residents, who often are out walking their pets and socializing, pay anywhere from $833 to $1,000 in monthly site rent. But they own the coaches. In fact, two recently sold for $140,000 and $168,000.

Barbara Cali, who co-founded the park with her late husband, Mark, in 1976, lives in Winchester Ranch and is staunchly opposed to a sale. But Cali said she no longer has the decision-making role in the business affairs of the park; it is owned by the family’s next generation, the Cali-Arioto Corp.

“We tried very hard to make a wonderful place for seniors,” she said. “This park is my baby. I want to die here. Special people are my neighbors, and that’s why this is so terrible.”

Pete Constant, the city councilman who represents the community, agrees that Winchester Ranch is the most desirable location in San Jose among retirees. The park is even on his daily walk, he said, because it’s so beautiful.

“And it’s right in the middle of this incredible synergy of development,” added Constant, who has taken no position on the possible sale but is talking to all the parties involved.

The Stevens Creek-Winchester area is bustling with Santana Row, expansion at Valley Fair Mall and redevelopment discussions concerning another large parcel that includes the domed Century movie theaters.

Last year, park residents learned that the ownership group was looking into a sale to developer PulteGroup — capitalizing on the land’s soaring value. In a statement, PulteGroup confirmed that it is exploring a purchase of the site for an undisclosed price. While Cali-Arioto has not yet applied with the city to convert the park, it is “relatively close,” the group’s broker said.

“San Jose has an ordinance that is well-thought-out and allows owners to close their mobile-home parks,” added Martin Chiechi, senior vice president for Cornish & Carey Commercial. “This ownership group plans to follow the letter of the law and do right by all the parties involved.”

Residents mobilized, forming a homeowners association and launching a public-information campaign to let city officials know of their plight.

“Many of us feel that the owners just thought we are doddering old fogies,” said Greathouse, who has lived in the park for more than eight years with her husband, Kent, now a part-time teacher. “But we have retired teachers, lawyers, businessmen. We’re not doddering old idiots. We know how to look out for ourselves.”

The city’s mobile-home park conversion ordinance, adopted in 1986, allows for owners to sell while ensuring fair compensation to residents. It even provides a time frame for residents to attempt to buy the park themselves. But to the best of anyone’s knowledge, the ordinance has never been used, so it’s unclear how much residents would receive if the City Council ultimately approved a land-use change.

“Our role will be to make sure that everything is 100 percent correct because we’re well aware that this will be scrutinized very closely,” said Laurel Prevetti, assistant director of the city’s Planning, Building and Code Enforcement department.

Constant said he understands how this is emotional for residents, but he also thinks that it is wrong to cast the ownership group as villains.

“It’s pretty clear to me that their goal here is not to throw a whole bunch of seniors out on the street,” he said. “They want people to feel good about this.”

But the harsh reality is, if forced to leave, residents would face a difficult housing environment. The median price for homes, townhouses and condos sold in January in Santa Clara County was $625,000. The average monthly rent for a single-bedroom apartment in San Jose is $1,825. And their current homes are mobile in name only, since they are anchored to their lots, and even if they could be moved, it’s unlikely that any new park would accept coaches built in the 1970s.

Dave Johnsen, 69, president of the homeowners association, said that 38 percent of park residents are at or below the federal poverty level, which is why he thinks many couldn’t afford to stay in Silicon Valley.

“It’s a hard situation,” agreed Leslye Corsiglia, director of the city’s housing department. “This is private property, but the community also has to balance the need for lower-income housing opportunities. It’s a challenge because Silicon Valley is just drastically underhoused. That’s why our rents are so high and why we have such traffic problems. And it’s only going to get worse.”

Whatever happens at Winchester Ranch, it won’t be quick. Converting mobile-home parks can be a drawn-out process.

Unlike many residents, Cali said she will be fine financially if the park were sold.

“But that’s not the point,” she said. “I want to live in my home.”

For now, they all wait in an uncomfortable limbo.

“There are people here who are housebound, and if you move them, I guarantee that within a few months they’re dead because the shock would be too much,” Johnsen said. “And if they can close this park, then every other senior park in the city is going to have a target on it.”

Follow Mark Emmons at Twitter.com/markedwinemmons.