EVERY WEEKDAY, LYNDA AVERS, 60, AN energetic grandmother of six, climbs into her red pickup and drives 10 miles from her 20-acre llama ranch to the Bedrock, Colo., post office to pick up her mail. Some of it, naturally, is addressed to her or her husband, Benton. But her most arresting correspondence is marked Mayor, Chamber of Commerce —or Fred and Wilma Flintstone.

Yes, Bedrock (pop. 12), an old mining town 65 miles northwest of Telluride, really is a place right out of history, thanks to Ayers, who volunteers her time—and her stamps—to answer letters from Flintstone fans. It all started 17 years ago when the local postmaster called Ayers, then a grade-school teacher, and told her, "I got a letter from a kid addressed Chamber of Commerce—Bedrock." Ayers said, "Put it in my box. I'll take care of it."

The 9-year-old correspondent, Scott Savant of Fults, Ill., hadn't figured on a Flintstonian response. But Ayers, who had learned about the show through her daughter and three sons, wrote back, signing herself Wilma. Soon similar letters began arriving, many of them routed there by postmasters who had learned to dump the Flintstone mail problem on the only Bedrock on the zip-code map. Usually she handles about half a dozen missives a month, but since the Flint-stones movie opened, Ayers says, she expects a rock slide. She answers all, on plain paper, though a local artist is designing her a stationery set featuring the Bedrock store. Over the years, Ayers notes, the letters haven't changed much. "They ask, 'Do you still have that silly plumbing and that silly car?' I tell them, 'As long as it works, why change it?''

Ayers works at a remove from Hanna-Barbera Productions, the company that owns the Flintstones. The executives there prefer fans to send mail to corporate headquarters (3400 Cahuanga Blvd., Hollywood, Calif., 90068), and they neither support nor publicly object to Ayers's activities. Meanwhile, she and Benton—who, in a delightful coincidence, actually operates heavy equipment in a quarry a la Fred Flintstone—haven't got around to seeing the movie. One reason is that she's too busy answering letters. Her original correspondent, Savant, still stays in touch, she says—though he is now 26 and spending a postgraduate summer in Paris—and there is a whole new generation wondering how that plumbing works. After all, Ayers reasons, "if there is a Bedrock, there's got to be a Wilma."