If "mesabroad.7z" is a file you need to open or submit, keep the following in mind:

Cash prizes are awarded to 1st, 2nd, and 3rd place winners in various grade categories, with matching amounts typically given to the student's teacher. Managing a .7z File

You will need a utility like 7-Zip or Keka to extract the contents.

"Mesa Through Time: Honoring Our Past, Inspiring Our Future". Eligibility: Open to students in grades K-12.