National forest in Idaho. Actually its 3 National forests combined... Over 3 million acres. They call it the River of No Return for a reason. You can pretty much completely disappear and sustain totally there. Assuming you can avoid being eaten by bears, falling from cliffs, and ya know a lil bit about winter survival.
Anyways, just wanted to throw a post out there for any others that wanna get lost from society....
(its a treacherous place, make no mistake about it... thats what makes it great!)