How much does the performance of one's high school affect one's personal college application?

Chance Me / Match Me!
1

I currently attend (and have attended for two years) a lower performing high school (Park Center Senior High) in a suburb of Minneapolis. I have been beginning to wonder if the overall performance of all the students in my high school, being fairly poor as far as state test scores, average GPA, and average ACT composite, will affect me as I apply to colleges the beginning of my senior year. This fall I am going to be a junior so I’m just starting to think about where I might want to go, so naturally I’ve spoken with a few of the top students in the class of 2015 to see what kind of schools they were able to be accepted into. The students in the class of 2015 with credentials similar to mine had a difficult time getting accepted into competitive universities, the best any student did was a waitlist (afterward accepted) to NYU. Most of them ended up at the University of Minnesota (Twin Cities), somewhat unfortunately. Could this be because the school itself is underperforming? Do colleges look at the performance of your whole school when deciding on your application?

As far as my qualifications:
Unweight 4.0 GPA (Rank 1/477) … (I doubt I’ll keep this all the way through, but I am sure to keep at least a 3.96)
I’ve taken the hardest courses available to me thus far and I am registered for the IB Diploma Program in the fall.
I’m expecting (and am fairly certain) that I will score between a 26-32 on the ACT.
EC:

  1. Captain of Mock Trial Team grades 11 and 12 (presumably 12, definite 11) and member for grades 9 and 10
  2. Model United Nations team (Grades 9-11, presumably 12)
  3. President of Sophomore Class Cabinet (1/2 of our the Student Council, grade 10 section, admitted for grade 11)
  4. Member of the Student Advisory Committee (The other 1/2 of the student council, all grades are a part of it, I was a member for grade 10 but likely not 11 or 12)

I guess the big question I’m asking is, do I have a chance at the top, most competitive universities despite the fact that I go to a school which is usually seen as poor and weak performing? The school does have the IB program, will this program deter admissions officers from the weak performance of my school overall?