Nearly 300,000 children in California—more than in any other state— are homeless, or live in cars, garages or crammed into single rooms with their entire families. More than half of those children are younger than 10 years old.

Most of them are in Southern California, in the state’s five most populous counties: Los Angeles, San Diego, Orange, Riverside and San Bernardino. But rural Trinity County has the state’s highest percentage of homeless students, followed by Santa Barbara, Sierra, Lake and San Bernardino.

The data, recently compiled by kidsdata.org and the California Homeless Youth Project, show that the number of homeless kids in California rose between 2011 and 2013 at a time when funding to aid them was tight.

The data likely understate the problem because some of the state’s school districts fail to identify children who are homeless or lack adequate housing.

Fully 40 percent of them, some in high poverty areas, reported that not a single student was homeless or living in inadequate housing last year, said Leanne Wheeler, who oversees programs for homeless students at the California Department of Education.

The federal McKinney-Vento Act defines homelessness broadly, including children whose families double up because they can’t afford their own places, as well as those who live in garages or shelters. The law requires school districts to identify students living in those conditions, and to provide services to help them stay in school.

“Because it’s an unfunded mandate, [school districts] do tend not to want to report because if they don’t report, they don’t have to do the services,” Wheeler said.

McKinney-Vento funding is limited and competitive, with only 80 of nearly 1,000 California districts receiving grants to serve homeless children.

The California Homeless Youth Project is calling on districts to more accurately identify homeless students, better inform them of their rights and address their specific needs in annual accountability plans they submit to the state, just as they must do with English learners or foster youth.

“Districts are supposed to remove every barrier to academic success,” said Melissa Schoonmaker, homeless education consultant at the Los Angeles County Office of Education.” Sometimes you’re asking for things that you would go—wow, that’s beyond the classroom,” Schoonmaker said.

But kids need counseling if they’re stressed about where they’re going to sleep, or if their families will remain together. Some families are fleeing domestic violence. Other children might stay out of school because they don’t have shoes, clothes or transportation.

The law also requires schools to enroll homeless kids immediately without immunization or academic records. Such children have the right to remain in school, even if they lose their housing and are forced to leave the neighborhood or the district.

Every school district is also required to hire a homeless liaison to help families exercise their rights under the law. Still, some districts appoint a liaison-in-name-only, someone who may have ten other responsibilities, Wheeler said.

But in the Rowland Unified School District, about 40 miles east of Los Angeles in the San Gabriel Valley, Monica Olmos said her sole job as homeless liaison is to ensure that kids have the foundation to succeed in school.

On a Tuesday morning in September, Olmos, 50, pilots her 1999 Dodge Intrepid—she calls it her rolling office— through winding streets where apple and pomegranate trees grow alongside low-slung stucco houses.

Thirty years ago, these were single-family homes, Olmos said. Some still are, but now others have every room rented out.

“There is hardly a garage that doesn’t have someone living in it.”

Twenty-six percent of the kids in the Rowland district fit the federal definition of homelessness, mostly because many live two, three or more families to a house.

It’s hard to find a place to do homework amid the chaos, Olmos said.

“There’s always a TV on. Someone else is playing music.”

Many people Olmos serves are undocumented, and barely get by with odd jobs, babysitting or street vending, so Olmos gathers food, clothing, bus passes and school supplies for the kids.

On this day, she’s going to check on a family that called her office because they couldn’t find relief from the 100-degree heat. She’s stopping in to visit one long-time client and delivering a middle school uniform for Maria Cortez’s 13-year-old son.

Cortez is petite and middle-aged. She opens a heavy iron screen door to reveal a tiny but well-organized living space. Cereal boxes and other foods are neatly stacked behind a sofa, chairs and TV. She has a visitor so Olmos says a quick goodbye.

“Monica has gotten us out of some tough situations,” Cortez said later by phone as she listed the crises resolved with Olmos’ help: helping her and the kids when her husband got violent and drank too much, getting counseling for her children, connecting her with parenting classes, food and clothes, even sending Santa Claus over one lean Christmas with presents for the kids.

Olmos and a colleague are also on the case of a couch-surfing 17-year old who was kicked out of his home and stopped attending a continuation school.

“We’re trying to save him,” Olmos said. “We all want for him to finish because a lot of jobs ask for diplomas.”

Olmos is one of two homeless liaisons in Rowland. It’s one of the county’s most successful programs, but it still struggles to survive.

Its funding—now about $500 thousand per year—has dwindled over the last decade, said Jennifer Kottke, who directs the program. “We’re in a huge crunch this year,” she said. But help from the school district, which provides just a small amount of the program’s funding has not been forthcoming.

“Our issues on this side of the district get kind of washed out,” she said.

“We see a lot that the administration doesn’t see,” Kottke said, adding that the administration wears blinders when it comes to the issues of homeless kids.

“Because we don’t want to chase people away from the district. But you can’t hide problems under the rug,” she said.

Still, the program has also shown that with support homeless kids can succeed.

“We’ve had kids go to high profile colleges. Kottke said. They’ve broken the cycle of poverty for themselves and their families.

Maria Cortez, whose 13-year-old is earning good grades, and whose older children have joined the military to make better lives for themselves, may soon count her kids among the success stories.

“My son once asked me why Monica is so concerned about us. I told him it’s because she wants kids like him to do better in life than their parents.”

Cortez said that after years of struggle, it looks like her kids are on track to do just that.