The Middle Branch of the Mad River is a 0.8 mile long (1.3 km) mountain brook

Stream

A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

 on the 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...

-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...

 border in the United States

United States

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

, within the eastern White Mountains

White Mountains (New Hampshire)

The White Mountains are a mountain range covering about a quarter of the state of New Hampshire and a small portion of western Maine in the United States. Part of the Appalachian Mountains, they are considered the most rugged mountains in New England...

. It is a tributary of the Mad River, a short feeder of the Cold River, part of 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...

 watershed

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

.

The Middle Branch flows east off the slopes of West Royce Mountain, beginning in New Hampshire and finishing in Maine. It joins the Mad River just upstream of Mad River Falls near the foot of the mountain.