Assabet River

General data
- Name: Assabet River
- Water system: Merrimack River
- Water type: River
- Progression: Concord River -> Merrimack River -> Gulf of Maine -> Atlantic Ocean -> Planet Earth
- Climates: Temperate
- Continents: North America
- Countries: United States of America
Description
The Assabet River is a small, 34.4-mile (55.4 km) long river located about 20 miles (30 km) west of Boston, Massachusetts, United States. The Assabet rises from a swampy area known as the Assabet Reservoir in Westborough, Massachusetts, and flows northeast before merging with the Sudbury River at Egg Rock in Concord, Massachusetts, to become the Concord River.