[1] It rises in Swains Lake in Barrington, 9 miles (14 km) west of Dover.

The river at one time provided water for swimming behind a dam at Bellamy Park in Dover.

This park was a favorite spot for local neighborhood children and young adults, but fell into disrepair in the late 1960s.

A short distance down the river from the park is the location of a former mill building, abandoned in the mid-20th century.

Beyond this dam the Bellamy River assumes its tidal nature, reverting to a small trickle at low tide.