Thousands of people have joined the search for a chest full of gold coins and jewels hidden by a New Mexico millionaire somewhere in the Rocky Mountains.

"I think it's out of control," 84-year-old Forrest Fenn, of Santa Fe, told ABC News affiliate KOAT. Five years ago, the art collector and author hid the 10-by-10 inch treasure chest in the mountains and then provided clues in his book "The Thrill of the Chase."

Scores of people- tens of thousands of people- have since scoured the mountains for the treasure, which includes 265 gold coins, gold nuggets, jade figures from ancient China, pre-Columbian gold animal artifacts and a handful of rubies, diamonds and sapphires, Fenn told the station.

The millionaire has remained silent on how much the hoard is worth. But the New Mexico Tourism Department estimates its worth $2 million.

Fenn expects about 50,000 treasure hunters will flock to the mountains this summer, up from 30,000 last summer. Although he provided many clues in a poem in his book, nine in all, only a few have come close to discovering the chest, Fenn said.

They were 200 feet away from the hiding place.

"A lot of people who are searching for the treasure don't see it the same way I do. I would love if someone found it tomorrow but if nobody found it for a hundred years, that's okay with me too," he said.

Fenn, a Vietnam War vet, said he decided to hide a treasure chest after he was diagnosed with terminal cancer in 1988.

"But mostly my motive was to get kids off the couch and away from their texting machines and out in the mountains," he told KOAT.