The river rises from a swamp south of Rockville Road (CT 138) in Voluntown. The river then flows due south to Green Fall Pond (41°31′52″N 71°48′32″W / 41.531°N 71.809°W / 41.531; -71.809), then continues south through North Stonington and into Hopkinton, Rhode Island where the river converges with Parmenter Brook to form the Ashaway River.

Below is a list of all crossings over the Green Fall River. The list starts at the headwaters and goes downstream.

• Voluntown
  • Sand Hill Road/Green Fall Rd. just south of the Green Falls Pond Dam near the Rhode Island border.
• North Stonington
  • Putker Road
  • Clarks Falls Road (CT 216) (Twice)

In addition to many unnamed tributaries, the following brooks also feed the Green Fall:

• Peg Mill Brook
• Palmer Pond Brook
• Glade Brook

• List of rivers in Connecticut
• List of rivers in Rhode Island

• Maps from the United States Geological Survey