If you are near Falmouth you can run him at Crane Wildlife Management Area. They have organized field trials there every so often. Stocked with pheasant and quail in season, so pretty decent cover for training. A lot of the Cape is just scrub oak, not the best for dogs unless that's where you hunt them.
Do a search on
www.masswildlife.org (fisheries and wildlife website) under where to go for other hunting areas. You can run your dog loose at any of them at any time of year.