What We Know: Last occupiers of nature preserve surrender

The last four occupiers of an Oregon nature preserve gave themselves up Thursday to the FBI. The surrender ended a nearly six-week standoff that began when a larger armed group seized the Malheur National Wildlife Refuge and demanded that the land be turned over to locals. Here's what we know:

— The final holdouts gave up without incident after the FBI surrounded the site. Federal authorities in six states arrested seven other people accused of being involved in the occupation. At least 25 people connected with the occupation have now been charged with conspiracy to interfere with federal workers.

— As the four turned themselves in, a leader in their movement was criminally charged in federal court. Cliven Bundy was arrested Wednesday in Portland after encouraging the Oregon occupiers not to give up. He is the father of Ammon Bundy, the jailed leader of the occupation. The elder Bundy was charged in a 2014 standoff at his ranch in Nevada. Federal authorities may have feared that his presence would draw sympathizers to defend the holdouts.

— It was unclear what effect the occupiers' presence had on the refuge or any of its archaeological artifacts. Online videos showed members of the group exploring buildings at the site and camping outside. At least one area was strewn with plastic water bottles, cardboard boxes, clothes, packages of bullets and beer cans.