WILLISTON – A 36-year-old Williston man was arrested on Tuesday after barricading himself in Fort Union Trading Post National Historic Site, southwest of Williston.

According to Williams County Sheriff’s Department information, with the assistance of the Williams County SWAT Team and the Northwest Crisis Negotiations Team, Ian Patrick Stewart was taken into custody on Tuesday and transported to the Williams County Correctional Center. Charges were pending.

Law enforcement was notified about 8 a.m. on Tuesday for a call for service regarding a disturbance, according to the sheriff’s department. The first responding deputy arrived at 8:14 a.m. Staff and visitors had safely vacated the property, and the site and the road to Fort Union were closed.

Early Tuesday afternoon, the sheriff’s department and several other agencies were involved in the ongoing response to Stewart barricading himself within Fort Union.

The Northwest Crisis Negotiations Team actively used verbal crisis management techniques to de-escalate the incident.

The road was reopened on Tuesday but Fort Union remained closed on Wednesday and the public was asked to continue to avoid the general area due to the ongoing investigation.