A Williston man arrested after barricading himself in Fort Union Trading Post National Historic Site, southwest of Williston, on Tuesday has been charged in Northwest District Court.

Ian Patrick Stewart, 36, was charged with one Class C felony count of burglary for the incident.

According to the affidavit of probable cause, Williams County Dispatch Center received a report shortly before 8 a.m. from a Fort Union Trading Post employee, who said they arrived at the property to open the fort when they encountered a male at the gate.

The employee reported the man was armed with a fire poker, and escorted them off the property. The employee observed the man possessing the donation box from one of the buildings, and the lock was broken from the bell tower building. The employee believed the suspect had driven a silver-colored van and responding law enforcement confirmed a Ford Transit van to be parked in the approach across from the fort, which was determined to be registered to Stewart.

According to the affidavit of probable cause, law enforcement confirmed that Stewart appeared to be barricaded within the fort. A drone was used to observe the scene from above, which identified Stewart as he walked around the property armed with one or more firearms.

Stewart was contacted by phone. He refused to exit the premises and threatened law enforcement if they attempted to enter the fort or encountered him. Stewart claimed he possessed 30 days worth of supplies during negotiations, and threatened to burn down the fort and destroy artifacts in its exhibits.

The Northwest Crisis Negotiations Team engaged verbal crisis management techniques to de-escalate the situation, and Stewart was taken into custody Tuesday afternoon by the Williams County Sheriff’s Department with assistance by the Williams County SWAT Team.

Stewart is scheduled to appear for a preliminary hearing on Wednesday, June 11.