Town of North Andover   http://www.townofnorthandover.com/Pages/index

Town of North Andover Trails & Open Space Rules and Regulations - http://www.townofnorthandover.com/Pages/NAndoverMA_Conservation/Just%20revised%20Rules%20%20Regs.pdf

Trustees of Reservations - http://www.thetrustees.org/index.cfm

Massachusetts Department of Conservation & Recreation (DCR) http://www.mass.gov/dcr/

Bay Circuit Trail - http://www.baycircuit.org/

Essex County GreenbeltAssociation - http://www.ecga.org/ 

Massachusetts Geographic Information System (MassGIS)  http://www.mass.gov/mgis/

Essex National Heritage Area - http://www.essexheritage.org/index.html

Ipswich River Watershed - http://www.ipswichriver.org/

Shawsheen River Watershed Association - http://www.shawsheen.org/

Cornell Lab of Ornithology - http://www.birds.cornell.edu/