@AppleNotFar , you’re right! 
No worries about math, @PossiblePrepMom , there are at least 2 years available past Calc BC, and independent study is available beyond that point. Academics are challenging, but there is real attention paid to how adolescents learn best and live best. It’s not a boot camp or a stress test; it’s a place where teens can really be at home and become - with guidance - their best selves.
Thank you everyone for such great recommendations. My son checked out all of them!