Updated

Fixated on computer screens and video monitors, an army of volunteers has been painstakingly reviewing hundreds of images and hours of footage recorded over the last four months, desperately hoping to find a single clue to the whereabouts of missing treasure hunter Randy Bilyeu.

The Colorado man disappeared in early January while searching for a $2 million cache of gold and jewels in northern New Mexico.

The recent discovery of a backpack on a rugged slope at Bandelier National Monument has re-energized the search for Bilyeu.

Based on what's inside, there's a strong indication the pack belonged to Bilyeu but authorities have yet to make an official determination.

As they wait for word, volunteers are focused on areas outside the monument. They launched a canoe trip down the Rio Grande on Thursday and a drone flight is planned this weekend.

Thursday marked four months since Bilyeu set out in his raft in search for the treasure. Ex-wife Linda Bilyeu says the family isn't giving up.