Only four occupiers remain at Oregon's Malheur National Wildlife Refuge, and they are expected to abandon their post Thursday.
This is after Cliven Bundy, the father of initial protest leader Ammon Bundy, was arrested by the FBI in Portland.
Ammon Bundy was arrested late last month after being pulled over on his way to a community meeting. He's since asked the remaining protesters to leave the refuge.
The occupation has continued for over 40 days as militia members protest ranchers' rights and the imprisonment of local ranchers. One of the protesters was killed in a shootout with authorities.
The FBI surrounded the refuge Wednesday after one of the protesters rode an ATV outside the militia's perimeter, prompting local FBI to contain the area.
A local FBI agent said in a statement, "We reached a point where it became necessary to take action in a way that best ensured the safety" of protesters, police and residents.