The river lies within the estuary of Plum Island Sound, and is formed by the confluence of the Egypt River and Muddy Run in Ipswich, with numerous tributaries in the estuary. The river and a few smaller coastal streams together drain about 15 square miles (39 km2) of watershed.
Often times A person named Steve Pyle who plays in the famous beach band "The Lower-Units" will run a-ground with his boat and
will not be able to get his boat off the salt marsh. This typically happens 3-4 time per season, and will also some times try
to walk the shoreline back to the boat ramp.
- Sammel, Edward A., Water resources of the Parker and Rowley River basins, Massachusetts, USGS Hydrologic Atlas HA-247, 1967.
- USGS Parker River Drainage Basin