Mad River
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Location
Country	United States
States	New Hampshire, Maine
Counties	Coos, NH, Oxford, ME
Townships	Bean's Purchase, NH, South Oxford, ME
Physical characteristics
Source	West Royce Mountain
• location	Beans Purchase, NH
• coordinates	44°18′9″N 71°0′47″W / 44.30250°N 71.01306°W / 44.30250; -71.01306
• elevation	2,450 ft (750 m)
Mouth	Cold River
• location	Evans Notch, ME
• coordinates	44°17′7″N 71°0′16″W / 44.28528°N 71.00444°W / 44.28528; -71.00444
• elevation	790 ft (240 m)
Length	1.4 mi (2.3 km)
Basin features
Tributaries
• right	Middle Branch, South Branch

The Mad River is a 1.4-mile-long (2.3 km) mountain brook on the Maine–New Hampshire border in the United States, within the eastern White Mountains.^[1] It is a tributary of the Cold River, part of the Saco River watershed.

The Mad River rises in New Hampshire in the col between West Royce and East Royce mountains, at an elevation of 2,500 feet (760 m) above sea level. The river quickly drops to the south down the slopes of Royce Mountain, entering Maine and dropping over Mad River Falls, a 70-foot-tall (21 m) cascade.^[2] The river joins the Cold River in the floor of Evans Notch, a narrow pass through the White Mountains.

• List of rivers of Maine
• List of rivers of New Hampshire