Before toy stores were stocked with pet plants, virtual pets and pillow pets, an advertising copywriter called Gary Ross Dahl was dreaming up the Pet Rock, a 1970s novelty toy craze since called a “ridiculously successful marketing scheme.”

It was meant as a joke — a “pet” for people who didn’t want to care for one. But it hit the market at just the right time. The Vietnam War had ended. Watergate was beginning. “There was a whole lot of bad news going on,” he told the Houston Chronicle in 1999. “People were down. It wasn’t a real good time for the national psyche. I think the Pet Rock was just a good giggle. Everybody needed a good laugh and the media ate it up.”

It’s that multimillion-dollar gag for which Dahl will be most remembered. The inventor died March 23 in southern Oregon from chronic obstructive pulmonary disease, his wife, Marguerite Dahl, confirmed Tuesday to theAssociated Press. He was 78.

Dahl was born in Bottineau, N.D., and raised in Spokane, Wash. He attended Washington State University and then pursued a career in advertising.

But his biggest business success occurred to him in the mid-1970s in a bar in Northern California. Sitting with some friends in Los Gatos, the conversation turned to pets — feeding them, cleaning them, training them — and he bragged that his animal never caused any trouble. “I have a pet rock,” he said, jokingly, according to the New York Times. Just for fun, he decided to try to sell it.

Dahl got some investors and went to work, putting small smooth stones in cardboard carriers that he filled with breathing holes. He added an owners’ manual with instructions on how to care for them. “If, when you remove the rock from its box it appears to be excited, place it on some old newspapers,” the original instructions said. “The rock will know what the paper is for and will require no further instruction. It will remain on the paper until you remove it.”

The Pet Rock hit the market just in time for Christmas 1975, selling for $3.95 each. Dahl and his wife started an assembly line in their small cabin in the Santa Cruz mountains, he told The Washington Post in 1977. But within six weeks, he needed another 300 people to get the job done. By the time the short-lived fad had fizzled out, he had sold some 1.5 million rocks,he once said.

With a production cost estimating about a penny per rock, he had pocketed a large chunk of change.

“Sure, we live differently today,” he told The Post in 1977. “We drive Mercedes instead of Hondas. Instead of a Franklin stove we’ve got real heat. And our swimming pool is bigger than that whole cabin.”

With his new-found wealth, his wife said he designed and built the Carry Nations Saloon in Los Gatos.

“Dahl got rich, got cocky, had a damn good time, opened a bar, bought a big house, drank too much,” the Houston Chronicle said. He “sold his bar, dreamed up a few clever but cataclysmic marketing flops, took up golf, got a real job, sued, got sued, felt betrayed.”

Dahl had a few notable mentions in the years that followed but none that overshadowed his rock in a box.

In 2000, he won the Bulwer-Lytton Fiction Contest for dreadful prose. His entry began: “The heather-encrusted Headlands, veiled in fog as thick as smoke in a crowded pub, hunched precariously over the moors, their rocky elbows slipping off land’s end, their bulbous, craggy noses thrust into the thick foam of the North Sea like bearded old men falling asleep in their pints.”

He also wrote a book called “Advertising for Dummies.”

In 2006, he and his wife retired and relocated to Jacksonville, Ore.

Still, years after his rock gimmick, he was remembered for the money-making phenomenon. “I’m sick of the whole damn thing,” he told the Houston Chronicle.

“Most inventors call me because they’ve come up with their own novelty idea,” he added. “A pet stick or pet poop or pet gravel. I’ve seen them all — they’re all bad.”

His wife agreed, telling the AP it was fun while it lasted. “Over time, however, people would come to him with weird ideas, expecting him to do for them what he had done for himself. And a lot of times they were really, really stupid ideas.”

Years later, Dahl was laying low, dodging the news media for fear that “a bunch of wackos” would come forward and threaten him with lawsuits, he told the AP in 1988. He said it made him think about what life would have looked like without rocks.

Via Washington Post