Ammon Bundy and a number of armed protestors have occupied a wildlife refuge in rural Oregon in protest of federal land management practices. It's just another incident in what some call the "Sagebrush Rebellion," which covers decades of conflict between Westerners, particularly farmers and ranchers, and the federal government's control and administration of both land and resources in the region.
The takeover of the remote facility was inspired in part to show support for a pair of local ranchers. Dwight Hammond Jr and his son Steven at the time were set to report to prison for an arson conviction from a wildfire they'd started. The Hammonds reported to prison anyway, disavowing any connection with anyone involved in an armed takeover of a federal facility.
Given that there has yet to be any violence, and given the remote location of the refuge, law enforcement so far has given the protestors a wide berth to avoid an incident.