I've always mistrusted the accuracy of labels on literary movements that are invented after the fact for our convenience (or, for example, the comically short-sighted way Pound came up with the name Modernism). Sartre and Camus as existentialists, for example. They were different enough to have a fued and break off their friendship, so there may have been a trend or some similarities, but to group them together is just laziness.
So I'm looking forward to reading some Snyder. I have an intuition that he may be similar to A. R. Ammons, although I have serious doubts whether anyone can outverse Ammons, one of the most pleasurable poets I've ever read. We shall see.