Students read books Feb. 20 at Wooden Valley Elementary School in Napa, Calif. More than 150 years after it was established, this one-room schoolhouse could fall victim to an economic crisis that threatens to close schools across the country.

Napa, Calif. ? In this rustic corner of California wine country, parents are fighting to prevent the closure of a one-classroom school established before the Civil War.

Near Las Vegas, families are trying to rescue two elementary schools with dwindling enrollment. And in a rural area outside San Diego, a 60-year-old schoolhouse closed because it had just seven students.

Rural schools such as these are being threatened as the economy forces deep cuts to education. Districts nationwide are preparing to shut down many campuses, and small, isolated schools are vulnerable because they serve fewer students and cost more per pupil to operate than larger schools.

“All over this country, the pressure is on to close rural schools,” said Marty Strange, policy director of the nonprofit Rural School and Community Trust in Arlington, Va. “They are a target in these hard economic times.”

Among the schools targeted is Wooden Valley Elementary School, which has one teacher, one teaching assistant and 20 students from kindergarten to fifth grade. Surrounded by ranches and vineyards in the rolling hills of Napa Valley, it is one of the oldest one-room schools still operating in California.

An icon of American culture depicted in the television show “Little House on the Prairie,” the one-room schoolhouse dominated education before buses allowed children to attend schools more than walking distance from their homes.

A century ago, there were more than 200,000 one-teacher schools in the country, but that number dwindled to 335 in 2006, according to the National Center for Educational Statistics.

In rural San Diego County, enrollment at Palomar Mountain School was only seven students when it closed last year after six decades.

Outside Las Vegas, school officials recently postponed a vote to close Lundy Elementary and Goodsprings Elementary after parents protested. Both schools have fewer than 10 students, and Goodsprings is listed on the National Register of Historic Places.

In Northern California, Wooden Valley has staved off closure many times before, but parents worry that the state’s budget crisis is so severe that it could finally shutter a school that has existed in some form since the 1850s.

District officials have proposed closing their two smallest schools to help offset $10 million in cuts to its $115 million annual budget. The 17,000-student district also is looking into increasing class sizes, shortening the school year and laying off nearly 10 percent of its 900 teachers.

California schools, which rank near the bottom nationally in per pupil spending, are preparing to make drastic cuts after Gov. Arnold Schwarzenegger and the Legislature last month reached a budget deal that reduces K-12 education spending by $8.6 billion — more than 10 percent — through June 2010.

“These cuts are completely devastating,” said Bob Wells, executive director of the Association of California School Administrators.

California school districts are set to increase class size, close libraries, eliminate sports programs, scrap electives such as art and music, and lay off tens of thousands of employees.

School officials say small schools like Wooden Valley are not cost-effective and that students can benefit from the resources of a larger school.

But advocates say that when rural schools close, children face longer commutes and parents become less involved. They also note that studies show that small schools lead to better grades and lower dropout rates.