Any budget issues?
So I wouldn’t apply to Cornell, Tufts, or Northeastern. I don’t think you’re in range.
I do think UMASS happens but looking at the stats (59% accepted), it is harder than other departments. They don’t give GPA and SAT stats for engineering.
I do think WPI, if you can afford it, is an in. I think RIT is also an in.
Given his love of bouldering and given the stats, the first school I thought of is UT Chattanooga. Stat wise - it’s a match and I know someone who bouldered there - so that’s sort of a local pick - living in Tennessee. MechE is ABET accredited. There’s lots of rock climbing in the region. Tennessee Tech won’t have as robust opportunities as UT Chatt but also is accessible for climbing.
Now for bouldering - is RIT, Umass, or Lowell the right place?
UT Chatt definitely is and shows up on a list of top rock climbing adjacent schools.
Others to consider (if distance isn’t an issue) - Montana State, Utah, Colorado State,
Good luck