Dennis is a superb craftsman and teacher. I'm not sure how many years I attended. It was extremely eye opening for me, a completely different approach from what I had been taught previously and much more suited to my own needs. I feel my career path was altered for the better by attending. I doubt I would still be in the business if it were not for those summer classes.
As to current offerings, not long ago James Tucker was offering classes(checkering, maybe more) at Lassen I believe. You will not find a finer stocker in America to than James.