Look for areas with a lot of exposed rock. Bald knobs or at least large boulders, these are most often the areas where the trees grow interesting shapes in dwarf form. Think "Yosemitie," only it doesn't have to be on a large scale... just big enough to have cracks or depressions for trees to grow in.
I don't know the area out there so you're on your own as far as location... but if you know what topography/landscape you're after you should be able to locate the right environment.
Other areas with harsh environments can work as well... bogs or even meadows where the shrubs are eaten/trimmed down or trampled by livestock and wildlife.
Rock is my favorite... the root systems are already confined to a tight space. Some come out easily, others take work and many should be left right where they are because it would cause too much trauma to the root system to get it out.
Good luck!