According to the Constitution, the State of Oregon owns the land. The Constitution is very clear about what kind of land and for what purposes the government of the United States can own land inside a sovereign state and what it can't.
A national wildlife preserve is not one of those purposes.
The state of Oregon and the representatives of Oregon should have stopped the declaration of a wildlife refuge. I would be willing to bet they supported it wholeheartedly. You must not be familiar with the state of Oregon - the voters on the coast and in Portland would probably vote to make the entire state into a wildlife refuge if it were up to them.
These are always complex issues, but the way to change it is to follow the rules and work on representatives to change it. It’s not to break the rules then allow anarchists to hijack the situation and create a confrontation. These militia guys breed the kind of moron who killed so many at the Murrah building in Oklahoma City. A real blow for liberty there, huh?