The caller is curious. He has just dialed the toll-free 800 number of the National Communications Center, a countryside telephone answering service for businesses using 800 numbers, and he wants to know where it is located. "Shingle Springs, Calif.," the operator tells him politely, adding, "That's halfway between Rescue and Latrobe."

The answer gets a laugh, as always, and then more questions. Because almost nobody, it seems, ever has heard of Shingle Springs. Or Rescue. And if a caller knows of Latrobe, he will tell you that it's Arnold Palmer's hometown, but that it's in Pennysylvania, not California.

Heading east from the flat delta of Sacramento on the way to South Lake Tahoe, Route 50 begins to climb into the rolling hills of California's Mother Lode country, where gold was discovered 131 years ago.

Shingle Springs sits on this rolling plain where herds of cattle graze about 25 miles east of Sacramento. Once a campsite for settlers moving westward, it is a tiny old town with one main street that used to be old Route 50 but is now called Mother Lode Drive. A green sign at each end of the street reads, in white letters

SHINGLE SPRINGS

Elev. 1,476.

Wooden shingles arn't made here anymore, but the mill still stands at the west end of town, across from the old railroad depot, which has been remodeled and turned into a clothing store.

Shingle Springs is an unlikely place to find the world's largest toll-free telephone service, the National Communications Center.

NCC has an 800-number answering service with more than 4,000 business clients, a marketing operation for telephone sales, an emergency medical information service and a toll-free phone service enabling persons to call if they have found a pet that is registered with their Pet Switchboard.

In the winter of 1976, Ben Gay III left the Bay Area in search of a small town in which to set up an answering-service business. Gay is an executive consultant to Sam Meo, who was assistant California treasurer under former Gov. Edmund G. Brown Sr. Meo had decided to open his own national toll-free phone service after becoming disenchanted with several other services he had used.

"I had been using answering services for a long time myself," he says. "And I had always been disappointed with them. This whole thing was an offshoot of my being dissatisfied."

Gay and Meo surveyed several small towns in Northern California and finally picked Shingle Springs. "We liked the quiet of the area," says Meo. "And the people are more stable. We have almost no turnover."

At first they had no clients. Gay moved to Shingle Springs and set up a small office in June 1976. He and NCC's first employe, Virginia Helm, an employed social worker before she was hired by Gay, sat around reading books and talking to each other. "We did that for about three months," Gay says. "That was a terible summer. I was sitting in my office one day, hoping the phones would start ringing, and I saw a big wall of flame coming across the hill outside the window. I didn't know how long we'd even be in business. The fire missed us, but it burned 50,000 acres around here."

By September, Gay says, "people began to hear about us, and the phones started ringing."

They haven't stopped since. In fact, business has boomed so that NCC has had to move its main telephone control centrer to Sacramento recently and go to a computer system. Its original employes-Helm, Jenell Wecker and Sue Kelsey, who started out as telephone operators-now run the company with Gay from the small office in Shingle Springs. They also answer calls inquiring about the service, as does Gay's wife, Marcia.

NCC has 65 full-time employes and, according to projections Gay and advertising consultant Bob Pettet have completed, will make about $5 million by the end of this year. The company has made it a point to hire older persons, it is a management policy to hire no one under 30. Employe average age is in the mid-40s.

"This is the strangest company I ever worked for," says NCC's office manager Mrs. Wecker, a longtime resident of Shingle Springs who used to drive the mail truck and work as a waitress at a restaurant in town before joining NCC. "I've never seen anything blossom so fast. Our gals love it, and they don't leave. It's like a big family and everyone treats it that way.

"We hire people who really need jobs and people, especially women, who want to be doing something. They have raised their children, but don't want to be retired. The people care about this company, they are concerned."

In return, Wecker says, NCC cares about its employes. It gives points for fast and good service by which workers can win trophies and prizes. It has an employe-investment program. If a person is sick for more than a day, Gay sends flowers. On an employe's birthday, the worker is given a signed black check to use in taking out his or her family for dinner.

"That kind of thing shows in people's work," Weckers says proudly. "The people here probably never had a job where they had any respect or anybody ever paid any attention to them. Everbody is treated the same. Everybody is treated the same. Bobody is Mr. or Mrs. anybody."

Weckr and Sue Kelsey, who worked at a decorative-bark factory nearby until joining NCC%, LAUGHED ABOUT THE EARLY DAYS OF THE BUSINESS.

"WHEN SUE AND I FIRST CAME TO WORK HERE," WECKER SAID, "THE PHONE RANG SO LITTLE IT SCARED YOU WHEN YOU HEARD IT. SUE USED TO NEEDLEWORK, I DID LEATHER-CRAFT, VIRGINIA READ A LOT AND BEN TALKED A LOT. NOBODY KNEW WE WERE HERE OR WHAT WE WERE DOING. I'D BEEN HERE ABOUT A MONTH AND MY YOUNGEST SON SAID, 'MOM, WHO ARE YOU WORKING FOR,THE MAFIA OR THE CIA?'"

Gay admits he is just about as secretive as the CIA when it comes to showing the telephone equipment to anyone. "It has become very scientific," he said. "It is really a very simple system, but I admit I am paranoid about competition seeing it."

NCC operators handle about 5,000 calls a day, explained Gay, ?and 93 percent of the calls are answered within 20 seconds of the customer dialing the last digit on the phone. I wouldn't want the competition to be able to do that."

Since opening, NCC has expanded to more than an answering service. It also operates a large national toll-free marketing service ("I think ours is the largest ad response number in the world," says Gay. "And we only use print media."): a "Pet Switchboard" for lost or injured animals that started a year ago, and an emergency medical information system called "The Body Guard," which began in August.

Gay says they have registered more than 50,000 pets across the country and anticipates increasing the number to 200,000 this year. For a $15 one-time fee, the pet owner registers his animal with the service and receives a collar tag listing an 800 number in Shingle Springs. If the animal is lost, all the finder has to do is cll to locate its owner.

"Last week we had a woman in New Jersey call," he says.

"She had found a tag in her front yard. We checked and found it belonged to her neighbor's dog two doors away. She couldn't believe she could call California fo find out the tag belonged to her neighbor's dog."

The company's newest service, "The Body Guard," costs $21 and already has enlisted 20,000 people. Persons who register wear a medallion, similar to a GI dog tag, which lists their registration number and an 800 telephone number.

Registrants complete a 12-page record of their medical histroy, including nay allergies to medication. If the person is injured or needs emergency medical help, the doctor can get his medical background by calling the 800 number.

Gay calls the service "a first-aid kit that you wear around your neck."

Shingle Springs seems little affected by time and creeping civilization. The store fronts of its main street have been remodeled, and its three hotels burned down years ago. But life is, residents say, slow and easy here.

Gay amuses visitors and his co-workers by telling Ben-Gay jokes. "People are always asking about my name," he says. "No, I am no relation to the backrub, I tell them. But I did name my son Ben Gay IV. Not Absorbine Jr."