Northern Arizona University (Flagstaff)
University of Utah (Salt Lake City)
Utah State University (Logan)
University of Alaska Fairbanks (Fairbanks)
University of Idaho (Moscow)
Washington State University (Pullman)
University of Washington (Seattle)
Colorado State University (Fort Collins)
University of Nevada Reno (Reno)
New Mexico Tech (Socorro) - more chem/earth than bio
I personally know biologists at each of these institutions and they are worth a look based on your son’s interests. Those are just the ones in the West that came to me off the top of my head.