The South River is a 10.6 mile

Mile

A mile is a unit of length, most commonly 5,280 feet . The mile of 5,280 feet is sometimes called the statute mile or land mile to distinguish it from the nautical mile...

 long (17.1 km

KM

KM, Km, or km may stand for:*Kilometre *Kernel methods*Kettle Moraine High School*Khmer language *Kuomintang , a centre-right political party in the Republic of China on Taiwan...

) river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in eastern New Hampshire

New Hampshire

New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...

 and 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...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is a tributary of the Ossipee River

Ossipee River

The Ossipee River is an river in eastern New Hampshire and western Maine in the United States. It is a tributary of the Saco River, which flows southeast to the Atlantic Ocean at Saco, Maine....

, which flows east to the Saco River

Saco River

The Saco River is a river in northeastern New Hampshire and southwestern Maine in the United States. It drains a rural area of of forests and farmlands west and southwest of Portland, emptying into the Atlantic Ocean at Saco Bay, from its source. It supplies drinking water to roughly 250,000...

 and ultimately the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

.

The South River begins at the outlet of Province Lake

Province Lake

Province Lake is a water body located on the border between New Hampshire and Maine in the United States. Approximately of the lake lie in the towns of Effingham and Wakefield, New Hampshire, with the remainder in Parsonsfield, Maine...

 in the town of Effingham, New Hampshire

Effingham, New Hampshire

Effingham is a town in Carroll County, New Hampshire, United States. As of the 2010 census, the town population was 1,465. Effingham includes the villages of Effingham Falls, Effingham , Center Effingham , and South Effingham...

 and proceeds north past the village of Center Effingham. Jogging east, the river enters Parsonsfield, Maine

Parsonsfield, Maine

Parsonsfield is a town in York County, Maine, United States. The population was 1,584 at the 2000 census. Parsonsfield includes the villages of Kezar Falls, Parsonsfield, and North, East and South Parsonsfield...

, then turns north again to reach the Ossipee River.