South Fork Malheur River

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

{{Infobox river

| name = South Fork Malheur River

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| name_etymology = From the French malheur (bad fortune), applied by French Canadian hunters whose cache of furs near the river were stolen{{cite book | last = McArthur | first = Lewis A. |author2=McArthur, Lewis L. | title = Oregon Geographic Names|edition=7th| publisher = Oregon Historical Society Press | year = 2003 |origyear=1928| location = Portland, Oregon | pages =606–07 | isbn = 0-87595-277-1}}

| image =

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| map_size = 300

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| pushpin_map = USA Oregon

| pushpin_map_size = 300

| pushpin_map_caption= Location of the mouth of the South Fork Malheur River in Oregon

| subdivision_type1 = Country

| subdivision_name1 = United States

| subdivision_type2 = State

| subdivision_name2 = Oregon

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| subdivision_type4 = County

| subdivision_name4 = Harney, Malheur

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| source1_location = Round Mountain, southeast of New Princeton, Harney County

| source1_coordinates= {{coord|43|13|40|N|118|24|24|W|display=inline}}{{cite web | work = Geographic Names Information System (GNIS) | publisher = United States Geological Survey | date = November 28, 1980 | url ={{Gnis3|1127302}} | title = South Fork Malheur River|accessdate=December 31, 2015}}

| source1_elevation = {{convert|4709|ft|abbr=on}}Source elevation derived from Google Earth search using GNIS source coordinates.

| mouth = Malheur River

| mouth_location = Riverside, Malheur County

| mouth_coordinates = {{coord|43|33|23|N|118|10|00|W|display=inline,title}}

| mouth_elevation = {{convert|3264|ft|abbr=on}}

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The South Fork Malheur River is a tributary of the Malheur River in a sparsely populated part of the U.S. state of Oregon. Arising southeast of the unincorporated community of New Princeton and slightly north of Oregon Route 78, it flows generally northeast to meet the Malheur near the unincorporated community of Riverside in Malheur County.{{cite web|title=United States Topographic Map|publisher=United States Geological Survey|via=Acme Mapper|url=http://mapper.acme.com/?ll=43.556389,-118.166667&z=12&t=T&marker0=43.556389,-118.166667|accessdate=January 1, 2016}} The South Fork enters the larger river {{convert|96|mi|km}} by water from its confluence with the Snake River.{{cite web|title=Malheur Unit Chapter of the Bulltrout Recovery Plan |url=http://www.fws.gov/pacific/bulltrout/RP/Chapter_14%20Malheur.pdf|format=PDF|page=1|publisher=United States Fish and Wildlife Service|accessdate=January 1, 2016}}