I found quite a few in Winterspring, but that may just be sheer dumb luck**. Look near where the elite frost giants are, there's a couple. I wasn't really *looking*, though, so I can't tell you if there's more. They're really easy to spot, too. I generally see them in the snow faster than on my radar. (Not that I ever have my mining radar on, anyways. Too many goddang other things to track.) So far, though, EPL seems the best.
** I never, ever find Thorium. Someone always mines it before I get to it. Doh.