Scores of school buses took to the fog-shrouded roads of Fauquier County yesterday morning, marking the start of another school year in the only Northern Virginia district to start classes before Labor Day.

Fauquier's early start is a result of its vast and varied topography and its miles of unpaved roads -- all of which make schools more likely to close when it snows. Virginia districts that regularly take at least eight snow days a year are allowed to begin classes before Labor Day, as fast-growing Loudoun County did until this year.

But Fauquier, still rural at heart, is coping with some of the same suburban growth issues familiar to anyone living in the Washington suburbs. Although it is still small compared with most Washington area districts, some of which add new students by the thousands and open a handful of new schools each year, Fauquier's 10,500 enrollment includes an increase of 500 this year, and the district opened a new middle school yesterday.

School Board Chairman Broni Lambelet (Marshall) drew this picture of the county's growth: In 1963, several small high schools were consolidated into Fauquier High School, which served the entire 600-square-mile county. In 1993, with Fauquier High overflowing, Liberty High School opened. Now, both schools are well over capacity and the School Board is planning a third high school.

"Here we are, 10 years later, back at the same place," Lambelet said. "It is exciting when a new school opens. But we would be happy if we didn't have to be in the business of building schools. We would rather focus on instruction."

One reason is the high cost, by Fauquier officials' standards. A new high school will cost at least $40 million, Lambelet said, adding, "There's never been a capital improvement program in this county, ever, for $40 million. We've never spent that kind of money before. We've never had to."

Now they must. Fauquier High School draws students all the way from far-flung northern communities such as Markham and Linden to the nearby, faster-growing neighborhoods around Warrenton. Enrollment is up 130 students this year, Principal Roger Sites said, and more are turning up every day.

In the halls of the 41-year-old school, built to hold 1,200 students, more than 1,700 bump and jostle their way to class. All the foreign-language teachers have classrooms in a trailer "village" next to the school. Savvy students know better than to push through the front lobby between class changes. Instead, they dart outside.

"The students are very respectful," Sites said. "They learn to live together in crowded conditions."

Some students also learn to cope with long rides on one of the county's 156 buses. Amber Durney, a 14-year-old freshman, lives in Hume, about 18 miles from Fauquier High. She gets up at 5:30 a.m. to make her bus at 6:25 a.m. and gets to school about an hour later.

"I love the country. I love the fact that it's a dirt road," Amber said. On the first day's ride, she saw a fawn in the road. But she recalls less pleasant journeys. "One time, in eighth grade, the roads iced over very quickly. We slid all the way down the mountain.

"The driver handled it well," she added.

Although Loudoun has lost its waiver and its early start, it is still coping with Fauquier-like transportation issues. The rule is that school districts can start early if they take an average of eight snow days in any five of the past 10 years, and Loudoun missed the average by a hair -- unhappily for administrators, because the county has one of the highest ratios of dirt roads in the state.

Loudoun schools Transportation Director Michael Lunsford said the county's 560 buses traverse 520 square miles, encountering traffic congestion even in less populous areas. "You go on some of the secondary roads, and what used to be five or six farms now is 15 or 20 houses," Lunsford said.

By comparison, Fairfax's 1,100 buses cover only 395 square miles and don't travel on unimproved roads, but there aren't many of those left in the county, said Linda Farbry, director of transportation services. Fairfax's challenges are traffic congestion and finding enough drivers, she said.

As Fauquier grows, it is in no particularly hurry to catch up to its more populous neighbors. Administrators say they are determined to keep a small-town feel to the school system, so Sites chats and jokes as he makes his daily rounds and Superintendent J. David Martin routinely gives his home phone number to parents.

"There's 10,500 students, but they shouldn't be faceless," Martin said.

Students crowd through the main corridor of Fauquier High School after the first day of school. The school is more than 500 students over capacity.Tenth-grade biology teacher Erin Wyld helps students onto the correct buses for the ride home from Fauquier High after the first day of school. Students board buses at Fauquier High. The county was allowed to start school early because it has taken several snow days in past years.