The Ellis River is a 23 miles (37 km) river in Oxford County

Oxford County, Maine

Oxford County is a county located in the U.S. state of Maine with a population of 57,833 as of the 2010 U.S. census. Its county seat is Paris.Part of Oxford County is included in the Lewiston-Auburn, Maine, metropolitan New England City and Town Area while a different part of Oxford County is...

 in western Maine

Maine

Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

. It is a tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Androscoggin River

Androscoggin River

The Androscoggin River is a river in the U.S. states of Maine and New Hampshire, in northern New England. It is long and joins the Kennebec River at Merrymeeting Bay in Maine before its water empties into the Gulf of Maine on the Atlantic Ocean. Its drainage basin is in area...

.

The river begins at the outlet of Ellis Pond in the northwest corner of Roxbury

Roxbury, Maine

Roxbury is a town in Oxford County, Maine, United States. The population was 384 at the 2000 census. Ellis Pond is popular with recreational fishermen.-History:...

 and flows southwest via a meandering course into Andover

Andover, Maine

Andover is a town in Oxford County, Maine, United States. The population was 864 at the 2000 census. Set among mountains and crossed by the Appalachian Trail, Andover is home to the Andover Earth Station and Lovejoy Covered Bridge.-History:...

, passing the village of East Andover before turning more to the southeast near South Andover. The river enters the corporate limits of Rumford and joins the Androscoggin at the village of Rumford Point.

From South Andover to the river's mouth, the Ellis River is followed by Maine State Route 5

Maine State Route 5

State Route 5 is part of Maine's system of numbered state highways, running from the an intersection with Route 9 in Old Orchard Beach, to an intersection with Route 120 in Andover. Route 5 is long....

. U.S. Route 2

U.S. Route 2

U.S. Route 2 is an east–west U.S. Highway spanning across the northern continental United States. US 2 consists of two segments connected by various roadways in southern Canada...

crosses the river just above its outlet to the Androscoggin.