NEW YORK (WPIX) — There’s a treasure hunt in the waters of the East River, off the Manhattan shoreline, prompted by a report by a prominent fossils collector on the country’s most popular podcast. However, the rush to find submerged treasure in city waters may prove as dangerous as it is elusive.

The search is for woolly mammoth tusks — thousands of them — allegedly dumped into the East River in the first half of the 20th century. Each tusk could be worth thousands of dollars if they’re actually there, so a growing number of bone hunters is in pursuit. 

Many tusks are found in places like the Koyukuk River Basin in Alaska. The East River, however, is nowhere near the massive, extinct mammals’ former habitats. Still, it became a magnet for treasure-seeking fossil detectives on Wednesday. 

That’s because, on Tuesday, Alaskan businessman and bone collector John Reeves appeared on “The Joe Rogan Experience,” the world’s most popular podcast.

“This is gonna be a bone rush,” Reeves said as he began reading what said was a draft report from the American Museum of Natural History.

The report, according to Reeves, said that some 500,000 mammoth tusks were dumped at a precise location along the East River between 1928 and 1958, but mainly around 1940.

Reeves finally read out the location after building up to it in the podcast episode. 

“The East River Drive and 65th Street,” he read from the apparent draft report, which referred to the FDR Drive before its name was changed. 

That’s where treasure seekers navigated the river on Wednesday morning and afternoon.

Possibly the most sophisticated of the bunch were the crew of a survey vessel, the Ronald P. Jensen. Captaining the boat equipped with $1 million worth of high-tech hydrographic devices was Connor Rogers.

“It’s a bone rush,” the geologist said. “[I said, at] 7 a.m., I’m going out there with the guys, and we’re gonna go start searching,” he said, describing a conversation he’d had with his father, Danny Rogers. The father-son team runs the family business, Rogers Surveying, PLLC, in Staten Island. 

“He didn’t argue,” Connor Rogers continued. “He was just like, ‘Okay, go find us some bones.'”

The holy grail was the tusks of woolly mammoths — elephant-size creatures that roamed the Northern Hemisphere for millennia until about 4,000 years ago. Each tusk can be worth as much as $20,000. So finding a large group of them could be a jackpot. 

Another much smaller boat appeared as they wound down their work. On board was a four-person dive team. They sent a diver into the water minutes after arriving.

They tried their luck until well after sundown, searching by hand, with a flashlight, in the murky water.

The Coast Guard, through a spokesperson, said that any vessel operating without lights in the East River, an active shipping channel, was putting itself at high risk. The Coast Guard was considering a formal warning on Wednesday evening. 

Rogers said they were capturing and analyzing images of the seabed floor, looking for any clues. 

“If it looks promising,” he said, “we’ll send a physical guy, a diver, down to put his hands on it.”

However, late Wednesday afternoon, the American Museum of Natural History cast major doubt on John Reeves’s claim to have a document showing that a half million woolly mammoth tusks had been dumped in the river.

“The American Museum of Natural History has no record of any such disposal, including no record of a paper published that alleges this.”