Gary Dahl, the inventor of the Pet Rock fad of the 1970s, died last month in Oregon. He was 78.

Gary Dahl Dies

Dahl died of chronic obstructive pulmonary disease, his surviving wife Marguerite Dahl confirmed Tuesday to NBC News.

Dahl introduced the Pet Rock to the masses in 1975 while he was working as a freelance copywriter in Los Gatos, Calif. He packaged smooth stones in a pet carrying case, which included instructions for “care and feeding.” Before the fad ran out of steam, Dahl sold roughly 1.5 million rocks for $3.95 each.

“People are so damn bored, tired of all their problems,” Dahl told People magazine in 1975. “This takes them on a fantasy trip — you might say we’ve packaged a sense of humor.”

Following the success of the Pet Rock, Dahl went on to write the book Advertising for Dummies. He also attempted to recreate a Pet Rock-type craze with similarly marketed items, such as “The Original Sand Breeding Kit,” which promised buyers a chance to “grow their own desert wasteland.”

Dahl is survived by his wife; sister Candace Dahl; children Christine Nunez, Eric Dahl, Samantha Leighton and Vicki Pershing; and seven grandchildren.