Nathan Pearce, Seneca Valley High School principal was never surprised that people would phone the 5-year-old school and ask what a Seneca Valley was?

"It sounds like a nursing home," said Pearce.

There is nothing that serene about the Screaming Eagles football team. It has become a household name (even if few know how to find the school) in the metropolitan area, having won 29 games in a row over a four-year period, including two state championships.

Located among the pastures in the northwest section of Montgomery County just off Rte. I-270 West, Seneca Valley found the perfect ingredient to bring together approximately 25 tiny communities that had barely heard of one another - football.

Perfection is in the Seneca Valley playbook. After beating Cambridge in the Maryland State Class B championship game, 41-13 in 1976, the Screaming Eagles' defensive unit went 61 quarters without allowing a point.

Sherwood snapped the string last week by scoring on a razzle-dazzle play in the first period.

"The kids were in a state of shock. It was strange to see Sherwood score after so many shutouts," said Pearce. "The kids were beginning to think we were invincible."

Seneca Valley came back to win, 22-7, to keep its streak alive. The area mark is 34 consecutive wins set from 1966-69 by Richard Montgomery.

But coach Al Thomas, is not too optimistic about his team's chances of breaking that mark.

"We only have six lettermen back and one of them has yet to play a game," said Thomas, who was an assistant at Gaithersburg for 10 years before coming to Seneca Valley. "We don't have a player that weighs 200 pounds. There are too many things against us."

Seneca Valley plays Bethesda-Chevy Chase tomorrow followed by games against Rockville, Wootton, Churchill and archrival Gaithersburg, Seneca Vally (3-0) is ranked third in the area while Gaithersbury (3-0) is fifth.

"Ironically, Gaithersburg is our 34th game. And it's their homecoming but we can't afford to look that far ahead," said Mike Pope, a senior running back. "Everything they win a game, they look at us. They want us. If we looked ahead to them, we might lose along the way."

Losing doesn't enter the minds of the 1,500 students or 82 faculty members. Many of the students are convinced it can't or won't happen.

"We're never going to lose. That's all there is to that," said tennis player Beth McCright. "I almost cried when Sherwood scored. The fellows worked so hard not to give up any points. That's the only thing we worry about, the points. We don't worry about losing."

The man given all the credit for putting Seneca Valley on the map is Thomas.

"He's organized to the minute. We get three-minute water breaks," said junior quarterback Robert Skalka. He knows everything about football. No one dares talk back to him. You don't have to. He's always right, anyway."

Although Thomas has been on the scene for only a short time, area coaches have already begun to cultivate him for his knowledge. Hal Sparks, the coach at Mt. St. Joseph's (Baltimore), calls once a week to discuss defensive strategy.

"He wanted our defensive schemes so I gave it to him, Thomas said, matter of factly. "He's been scored on just twice in four games."

Seneca Valley already is overcrowded. The auditorium cannot hold the school population and two assemblies have to be held each time a program is scheduled. The county is building additions since the projected student enrollment is expected to increase by a fourth by next year. The school will be classified as a AA school in 1979.

"We've gone from a B school to an A in three years. We'll be in the highest class next year," said Pearce. "That's growing in a hurry. That can be good and bad. The larger the school, the more students you can involve in activities. On the other hand, you lose some of the personable relationships."

Most of the students and teachers agree the success of the football team has done wonders for the partly urban, partly rural school. There is no fire station or shopping center nearby. The team is everything.

"I knew how good the team was when I went to junior high," said sophomore Michelle Parsons, "People would always talk abouto Seneca Valley. I couldn't wait to get here."

The huge football trophies proudly displayed in the case in the main hall recently been surrounded by awards for boys' and girls' cross country, tennis, gymnastics and wrestling.

"Everyone is doing something, now. Once the kids looked up to us, put on a pedestal," said senior back Kervin Ridgley. "Not any more. Even the teachers have cracked down on us. We don't get away with anything."

Since the Eagles began their amazing string, dozens of area teams have called Thomas seeking to arrange games. But the county's football schedule doesn't allow too many open dates for out-of-league competition.

"We'd love to play some of the other schools around the area. I think we'd do all right," said Ridgley.

Thomas a fidgety sort who at times wears his green and yellow cap backwards, thinks nothing of a George Allen-style 3 1/2-4 hour practice.

"We stay out here until we get it right," Thomas is fond of saying.

Thomas' daily practice routine resembles a drill sergeant taking his troops on a march with full packs. He often runs a play repeatedly, pointing out each mistake and praising each good move.

After one cornerback missed an assignment that resulted in a pass completion. Thomas stood with his head cocked to the side and his hands' on his hips for several seconds before bellowing at the player.

"OK, coach I'll get it," the player said.

"Yeah, you'll get it. When? This is our fourth game," said Thomas, turning away.

Thomas, who rarely smiles during practice, couldn't help but break into a wide grin when punter Gary Baumardner, who had just boomed a ball far downfield, asked if he could use a softer ball in the game.

"You kick them 60 yards out here and 21 in the game. No, you can't use a special ball to punt," said Thomas.

The Seneca Valley players are loose and free-spirited despite Thomas occasional tirades. Most of them ignored the farmer cutting his corn less than 200 yards away and listened attentively white Thomas showed another option off his wishbone offense.

Midway through the practice session, two players swing at each other, causing most of the players to break into laughter.

"What's going on here?" Thomas asked. "Let's have no more of that. Neither one of you could hurt each other if you wanted too. Let's save our fighting for Saturday."

Nearby, an enthusiastic band of cheerleaders was going through a routine that ended with the words. "We are the champions of the world."

Perhaps not the world champions, but definitely kings of the valley.