For more than two decades, Mr. Bell, who was 72 when he died April 13 at his home in Pahrump, Nev., stayed up all night talking to those people on the radio, patiently encouraging them to tell their stories about alien abductions, crop circles, anthrax scares and, as he put it, all things “seen at the edge of vision.” The Nye County, Nev., sheriff’s office said an autopsy will be conducted to determine the cause of death.

At Mr. Bell’s peak in the 1990s, his show, “Coast to Coast AM,” was on more than 400 radio stations. He took calls all night long, alone in the studio he built on his isolated homestead in Pahrump, in the Nevada desert. He punched up the callers himself, unscreened, keeping one line just for those who wanted to talk about what really happened at Area 51, the U.S. government reserve that for decades has been a locus of UFO sightings and purported encounters with alien beings.

Long before fake news became a political topic, Mr. Bell made a good living encouraging Americans to accept the most fantastic and unlikely tales, to believe that we are not alone, to accept that in a world where the pace of life seemed to quicken with every passing year, there were forces from beyond that were trying to tell us something.

In about 40 cities around the country, and in London and Tokyo, Art Bell Chat Clubs met regularly to hear talks by ufologists and by people who described their near-death and past-life experiences. He also had more prominent guests on the show — singers, comics, actors, scientists.