In a way, I'm a little surprised that so much of the West on the map is not covered with forest.
There's an obvious large amount of grass and sagebrush terrain. The forested mountains should be ironed out flat! No, I take that back ... I like the vertical landscape.
around here, if we stop clearing an area it will be taken back over with trees within 10 - 20 years. we do have seed forests around so that would happen.
in other areas where they've cleared the woodlands it would take longer for the surrounding areas to move back in, but it would happen.