add license info for Air Base Speedway
add Rogers Island opposite Fort Edward
map sections of Erie Canal from Rotterdam to and passt Schoharie Creek
extend and adjust schenectady segment of Erie Canal
add schenectady segment of Erie Canal
Rexford Aquaduct and canal approaches
improve routing of Enlarged Erie Canal in Cohoes NY
improve routing of Enlarged Erie Canal in Cohoes NY
sections of Enlarged Erie Canal visible today
sections of Enlarged Erie Canal visible today
sections of Enlarged Erie Canal visible today
add Old Canal (Champlain Canal) at Fort Edwards, NY
improve enlarged erie canal, cohoes NY
improve erie, champlain canals through cohoes NY
add start date for Champlain Canal
complete champlain canal from Waterford to section previously mapped by Natfoot
add section of old Champlain canal still visible in modern imagery