I am going to try to be kind and honest at the same time! First of all, your stats seem very strong! A 1500+ SAT score and 10+ AP Classes are really good! All of the schools you listed are reaches for EVERYONE. Your grades might be of some concern to these schools - although you did show an upward trend. As long as you provided a solid reason for this (that fact that you were immature, as you put it, is obviously not a good one). Your EC’s seem good, though there is nothing that jumps out to me that screams “ADMIT THIS STUDENT!”. This doesn’t mean you won’t have a decent chance of getting into competitive schools, though the reason will likely be your impressive test scores and (hopefully) compelling essays, rather than your EC’s.
I would highly advise you to think about your TARGET schools. Schools that you would be perfectly happy attending, but you will have a better chance of getting in than say, Bowdoin (which has a 7% RD acceptance rate). I have a feeling you will not be satisfied at St. Lawrence, so let’s make sure you get into some other awesome schools! You might have an edge in Middlebury (my brother’s alma mater), since you attended their program. My brother can attest for their very small yet strong math program!
This may be a bad move on my part, since I am applying to most of these schools, but here are some suggestions! For you, I would say your target schools range from a
25-40% acceptance rate (that’s my range, I have lower test scores but higher grades and perhaps more compelling EC’s, no offense!). These are the targets I am applying to, which you might be interested in:
Conn College (38%) - I think that you will very easily get into this school, since it is in your state, and its acceptance rate is pretty high for a target school. Very small, but beautiful campus! I am also applying here RD.
Oberlin College (36%) - Definitely NOT a New England school, but still awesome! Their STEM programs are actually known to be hidden gems within this school. Also applying here, though I am attracted to it mainly because of its performing arts and progressive history and environment!
Vassar College (25%) - This might be a target-reach classification. Very strong liberal arts schools, known to be similar to Yale if Yale is your cup of tea (it certainly is mine, since I am applying REA there!).
Hope this helps! I am sure you will get into at least one of your reach schools, but it never hurts to have some back-ups.