Massachusetts and New England:

http://www.anselm.edu/internet/compsci/faculty_staff/mmalita/contest/ St. Anselm College, NH

http://www.fitchburgstate.edu/academics/academic-departments/computer-science-dept/high-school-programming-contest/ Fitchburg State

http://web.cs.wpi.edu/Resources/Contest/ Worcester Polytechnic Institute

http://6.470.scripts.mit.edu/2013/ Massachusetts Institute of Technology’s 6.470

http://www.battlecode.org/info/ Massachusetts Institute of Technology's 6.370 Battlecode

Providence College

Bristol Community College

 

From across the US:

https://code.google.com/codejam Google Code Jam

http://ccscne.org/participate/programming-contest/ CCSCNE CS Ed

http://www.botball.org Botball

https://picoctf.com/about  Carnegie Mellon University

http://www.usaco.org/ USA Computing Olympiad (USACO)

http://icpc.baylor.edu/ ACM International Collegiate Programming Contest (ICPC)

http://projecteuler.net/problems Project Euler

http://www.hpcodewars.org/ HP CodeWars

http://community.topcoder.com/tco13/ TopCoder Open

http://www.acsl.org/ American Computer Science League

http://www.continentalmathematicsleague.com/ Continental Math League Contest

http://www.cs.sbu.edu/contest/ St. Bonaventure University High School Programming Contest

http://www.zerorobotics.org/ The Zero Robotics SPHERES Challenge competition

 

International, US teams are welcome to participate:

http://www.spoj.com/contests/  Polish high school programming contest

http://www.cemc.uwaterloo.ca/contests/computing.html  Canadian CS contests (US teams can participate but are not awarded prizes)

http://cscircles.cemc.uwaterloo.ca/ Canadian training site in Python

http://uva.onlinejudge.org/ ICPC Universidad de Valladolid training site

http://www.codechef.com/ CodeChef - India's Largest Programming Competition

http://icfpcontest.org/ International Conference on Functional Programming Contest

 

Suggested resource:

Top 10 Ways to Increase Girls' Participation in Computing Competitions: https://www.ncwit.org/resources/top-10-ways-increase-girls-participation-computing-competitions/top-10-ways-increase-girls