By my senior year of HS, I was doing probably low to mid 40's a week during the season with 6 days a week, while (inconsistently) peaking at low 60's once or twice in the off-season. I never ran more than probably 63 miles ever in a single week of high school.
Granted, my coach was having us do quality workouts at least once a week, but the kids on my team were always coming into college with good PRs (15+ guys at sub-16:20, 9:30, 4:25, 1:56-type during my four years). None of us logged our miles religiously also, so we were running much more organically rather than trying to micro-manage our mileage.
Our coach also had us run more for minutes than miles usually, we kept track of our mileage more for pacing reasons than anything.
The team I ran happened to also podium all four years at our state championship meet, and I ran in one of the toughest states in the nation to do that in.
My high school PR's were 16:00, 4:13, 1:53.
I see too many kids now in college burn out and not meet expectations, partly due to their high school coaches running them into the ground with too much mileage during their HS careers. I think high school should definitely be a learning curve of quality over quantity in order to produce success both instantaneously as well as for long-term careers.