The Putney School is also a bording school in Putney, Vermont in the progressive tradition of those sorts of things. I go there. It has a long history of rampant drug use and pretty good education. According to rumor, it was at one point the hub of LSD distribution for much of southern Vermont.
If you're thinking of applying, bear in mind that the Philosophy of the place has bent towards the conservative end of things recently. I'd also recommend reading the course lists, because, being a small school, there's a limited selection of classes.