Environmental Guidelines for Horse Owners - British Columbia
http://www.agf.gov.bc.ca/resmgmt/fppa/pubs/environ/horse/horse08.htm

Horse Manure Composting - NC State University
http://burke.ces.state.nc.us/pubs/horse/compost.shtml

Horse Manure Management - Ohio State University
http://ohioline.osu.edu/b604/b604_11.html

Horses for Clean Water
http://www.horsesforcleanwater.com

King County, WA Program to Collect Horse Manure
http://dnr.metrokc.gov/dnradmin/press/2001/x10321hm.htm

Manure and Pasture Management for Recreational Horse Owners
http://www.extension.umn.edu/distribution/naturalresources/DD7540.html

The Seattle Times - Horse Manure Problem
http://seattletimes.nwsource.com/html/localnews/134344312_muddyhorse21m.html