BOISE -- An Illinois resident missing since the beginning of the month has been found dead, less than a week after a wanted man was arrested in Boise while driving his van.

The body of 62-year-old John Cumby Jr. was found in the mountains west of Denver late last week.

Cumby was reported missing from Rock Falls, Illinois after he didn't return from a camping trip in the Denver area.

The missing-persons case took a strange turn when Ada County Sheriff's Office deputies stopped 25-year-old Jeffrey Maynard for erratic driving on Interstate 84 Sept. 10. Maynard was driving Cumby's blue Plymouth van, and had several of his possessions, including his wallet and ID.

Maynard could not explain to deputies why he had Cumby's van and personal items, or where the other man was.

MORE: Man caught driving missing person's van on I-84 arrested

Sheriff's officials say Maynard had active warrants for theft and attempted arson out of Texas. During the traffic stop, deputies say the suspect also grabbed a can of mace when asked to step out of the van, but dropped it when the deputy noticed what he was doing.

Maynard was arrested on charges of assault and battery on an officer and providing false information to law enforcement. He remains held in the Ada County Jail on a $500,000 bond.

Officials have not yet determined how Cumby died, and Maynard has not been charged in his death.

Idaho authorities are working closely with police in Illinois and Colorado. The case remains under investigation.