Minuteman Babe Ruth League
- Spring baseball league for players of ages 13-15 in the towns of Concord, Carlisle, Maynard, Stow, Sudbury, Lincoln, Wayland, Westford, and Weston.
- http://www.mmbrl.com/

Groton Dunstable Youth Soccer Club
- Field maps, registration information, and club calendar.
- http://www.gdysc.org/

Planet Tennis USA
- Runs camps in Dunstable, Lowell, Townsend and Tyngsboro for youth from 5 to 16.
- http://planettennisusa.com/

FellsBiker.com
- About mountain biking in the Middlesex Fells Reservation. Includes maps, photos, and trail information.
- http://www.fellsbiker.com/

AMHL.com
- Morning ice hockey program for adults. Includes downloadable schedules (Microsoft Excel format), player profiles, statistics, rules, and photos. (Concord-Carlisle)
- http://www.amhl.com/

Acton Boxboro Youth Soccer
- Provides calendar, coaches guide, uniform information, and field maps.
- http://abys.org/

Acton Boxboro Youth Hockey Association
- Provides newsletters, program and team information, photo gallery, and merchandise.
- http://www.abyha.org/

Dover/Sherborn Soccer Club
- Provides schedules, registration information, and articles.
- http://www.dssoccer.net/

SMS Youth Hockey Association
- Information about the youth hockey program, serving Bolton, Clinton, Lancaster, Maynard, Stow, and Sudbury.
- http://www.smshockey.com/