Law enforcement was able to return only about a dozen of the artifacts to museums, Williams said.
About the same time, Stevens decided to turn himself in and hired Watson to contact the BLM. Stevens still had some of the stolen items and was willing to return them and cooperate, Watson said.
Stevens admitted stealing artifacts and guns from museums in Hardin, Virginia City and Dillon. Investigators also conducted interviews and searches in California.
Watson said as part of a plea agreement, Stevens' estate will pay the nine Montana museums $5,000 each. Watson said the thefts escalated after a 2002 fire destroyed his home along with a priceless collection of museum-quality items.
"His behavior became so aberrent, he finally had to come to terms that he was out of control," Watson said Wednesday.