>> reporter: dale nightel and cynthia mechum among perhaps thousands looking for this bronze chest, saidwith a bounty of gold and rare artifacts. but only one man says he knows where it is. >> here's a wonderful artifact. this is a lantern. see the wick? >> reporter: forrest fen is an 87-year-old former military pilot turned wealthy antiques dealer. he claims in 2010 he hid the treasure somewhere in the rocky mountains. why would you do that? >> well, in 1988 i was diagnosed with what everybody thought was terminal cancer. decides that, we were going into a recession. and i just wanted to give some people hope. >> reporter: fen's health recovered. >> going inside the vault here. >> reporter: the idea of creating a modern-day treasure hunt stuck with him. >> there's 265 american gold eagles and double eagles. there's ancient middle eastern gold coins. there's hundreds and hundreds of gold nuggets. two of them as big as a hen's egg. >> reporter: he says even he doesn't know what it's all worth. >> writers have appraised it between $1 million and $5 million. >> reporter: he estimates around