Mad River (Cocheco River tributary)

{{Use American English|date=February 2025}}

{{Infobox river

| name = Mad River

| name_native =

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| image = Mad River Farmington NH.jpg

| image_caption = Ledges near River Road in Farmington, NH

| map =

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| pushpin_map = New Hampshire#USA

| pushpin_map_size = 250 px

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| subdivision_type1 = Country

| subdivision_name1 = United States

| subdivision_type2 = State

| subdivision_name2 = New Hampshire

| subdivision_type3 = County

| subdivision_name3 = Strafford

| subdivision_type4 = Town

| subdivision_name4 = Farmington

| subdivision_type5 =

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| length = {{convert|5.2|mi|km|abbr=on}}

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| source1 = Nubble Pond

| source1_location = Farmington

| source1_coordinates= {{coord|43|21|4|N|71|6|1|W|type:river|display=inline}}

| source1_elevation = {{convert|715|ft|m|abbr=on}}

| mouth = Cochecho River

| mouth_location = Farmington village

| mouth_coordinates = {{coord|43|23|11|N|71|4|2|W|type:river|display=inline,title}}

| mouth_elevation = {{convert|270|ft|m|abbr=on}}

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The Mad River is a {{convert|5.2|mi|km|adj=mid|-long}}[http://www.granit.unh.edu New Hampshire GRANIT state geographic information system] river in eastern New Hampshire in the United States. It is a tributary of the Cochecho River, part of the Piscataqua River watershed leading to the Atlantic Ocean.

The river is located entirely in the town of Farmington. It rises in Nubble Pond, between Nubble Mountain and Hussey Mountain, and flows northwest, then northeast, reaching the Cochecho near the town center of Farmington. The river drops more than {{convert|500|ft|-1}} over its {{convert|5|mi|adj=on|0}} route, in places falling over scenic ledges.