San Diego Park & Recreation
http://www.sandiego.gov/park-and-recreation/
San Diego County Water Authority Mission Trails Project
http://www.sdcwa.org/infra/cip-missiontrails.phtml
Santee Recreation
http://www.ci.santee.ca.us/csd/activities.htm
The California Chaparral Field Institute - one of the best sites
on chaparral and wild fires in California
http://californiachaparral.org/contactlinks.html
San Diego Natural History Musem
http://www.sdnhm.org/index.php
Earthguide Online Classroom
http://earthguide.ucsd.edu/eoc
Project Wildlife
http://www.projectwildlife.org/
S. D. Mountain Biking Association
http://www.sdmba.com/
S. D. Astronomy Association
http://www.sdaa.org/
S. D Mountain Rescuehttp://www.sdmrt.org/
S. D. River Park Foundation
http://www.sandiegoriver.org/
S. D. Tracking Team
http://www.sdtt.org/
S.D. Founders' Trail Associates
http://www.earlysandiego.org/
S. D. Archaeological Center
http://www.sandiegoarchaeology.org/index.html
GoCityKids
http://www.gocitykids.com
For information on mountain lions and California wildlife. California Department of Fish and Game. http://www.dfg.ca.gov
For information on rock climbing in the San Diego area including Mission Trails. http://members.cox.net/sandiegorock/