The general rule for a resume is:
1) If you have only been through one or two years of college, list activities from the past 4 years.
2) After that, only list things you have done since the beginning of college.
The summer before high school and college is a bit of a gray zone, but I don't think it would hurt to include the activity on a resume or AMCAS application. Worst case scenario, someone will decide to ignore it.