List of longest undammed rivers

{| class="wikitable"

!colspan="6" align="center"| Continent color key

|bgcolor="#FFCBCB"|Asia

|bgcolor="#FFCCFF"|Europe

|bgcolor="#CCFFFF"|North America

|bgcolor="#CCFF66"|Oceania

|bgcolor="#FFEBAD"|South America

{| class="wikitable"

!colspan="6" align="center"| Length color key

|bgcolor="#7B68EE"|{{convert|3000|to|5000|km|mi}}

|bgcolor="#1E90FF"|{{convert|2000|to|3000|km|mi}}

|bgcolor="#6495ED"|{{convert|1000|to|2000|km|mi}}

|bgcolor="#00BFFF"|Less than {{convert|1000|km|mi}}

!

!River

!data-sort-type = number|Length

!data-sort-type = number|Drainage area

!data-sort-type = number|Average discharge (m³/s)

!Mouth

!Notes

!Reference

!Rank

|Amazon River

|bgcolor="#4169E1"|{{convert|6937|km|mi|abbr=on}}
{{convert|6992|km|mi|abbr=on}}

|{{convert|7050000|km2|mi2|abbr=on}}

|{{convert|219000|m3/s|cuft/s|abbr=on}}

|Atlantic Ocean

|Second-longest and largest river in the world, undammed as well as unbridged, does not form a delta while joining the sea due to adequate thrust of river water to overcome the sea water wave and tidal thrusts.

|

|1

|Lena River

|bgcolor="#7B68EE"|{{convert|4472|km|mi|abbr=on}}

|{{convert|2500000|km2|mi2|abbr=on}}

|{{convert|17000|m3/s|cuft/s|abbr=on}}

|Arctic Ocean

|Longest undammed river in Asia.

|

|2

|Amur–Shilka–Onon

|bgcolor="#7B68EE"|{{convert|4197|km|mi|abbr=on}}

|{{convert|1855000|km2|mi2|abbr=on}}

|{{convert|11700|m3/s|cuft/s|abbr=on}}

|Strait of Tartary

|

|

|3

|Mackenzie–Slave–Athabasca

| bgcolor="#7B68EE" |{{convert|3403|km|mi|abbr=on}}

|{{convert|1805200|km2|mi2|abbr=on}}

|{{convert|10700|m3/s|cuft/s|abbr=on}}

|Arctic Ocean

|The Peace–Finlay system would extend even longer from the head of the Slave but there are dams on the Peace.

|

|4

|Nizhnyaya Tunguska River

| bgcolor="#1E90FF" |{{convert|2989|km|mi|abbr=on}}

|{{convert|473000|km2|mi2|abbr=on}}

|{{convert|3680|m3/s|cuft/s|abbr=on}}

|Yenisei River

|The Russian government is planning to build hydro dams on the river within the next few years.

|

|5

|Salween River

| bgcolor="#1E90FF" |{{convert|2815|km|mi|abbr=on}}

|{{convert|324000|km2|mi2|abbr=on}}

|{{convert|6700|m3/s|cuft/s|abbr=on}}

|Andaman Sea

|Longest undammed Southeast Asian river. Burma is planning to build the Tasang Dam and several others.

|

|6

|Paraguay River

| bgcolor="#1E90FF" |{{convert|2549|km|mi|abbr=on}}

|{{convert|1150000|km2|mi2|abbr=on}}

|{{convert|4550|m3/s|cuft/s|abbr=on}}

|Paraná River

|

|

|7

|Amu Darya–Panj

|bgcolor="#1E90FF"|{{convert|2500|km|mi|abbr=on}}

|{{convert|534700|km2|mi2|abbr=on}}

|{{convert|1330|m3/s|cuft/s|abbr=on}}

|Aral Sea (former)

|Although undammed, heavy diversion through canals causes the river to frequently dry up without reaching its mouth. Tajikistan is planning to build a hydroelectric dam on the Panj River.

|

|8

|Aldan River

|bgcolor="#1E90FF"|{{convert|2273|km|mi|abbr=on}}

|{{convert|729000|km2|mi2|abbr=on}}

|{{convert|5060|m3/s|cuft/s|abbr=on}}

|Lena River

|

|

|

|Rio Negro

|bgcolor="#1E90FF"|{{convert|2230|km|mi|abbr=on}}

|{{convert|691000|km2|mi2|abbr=on}}

|{{convert|29300|m3/s|cuft/s|abbr=on}}

|Amazon River

|

|

|

|Vitim River

|bgcolor="#6495ED"|{{convert|1978|km|mi|abbr=on}}

|

|

|Lena River

|

|

|

|Indigirka River

|bgcolor="#6495ED"|{{convert|1726|km|mi|abbr=on}}

|{{convert|360400|km2|mi2|abbr=on}}

|{{convert|1810|m3/s|cuft/s|abbr=on}}

|Arctic Ocean

|

|

|

|Fraser River

|bgcolor="#6495ED"|{{convert|1375|km|mi|abbr=on}}

|{{convert|220000|km2|mi2|abbr=on}}

|{{convert|3475|m3/s|cuft/s|abbr=on}}

|Pacific Ocean

|

|

|

|Kuskokwim River

|bgcolor="#6495ED"|{{convert|1165|km|mi|abbr=on}}

|{{convert|120000|km2|mi2|abbr=on}}

|{{convert|1900|m3/s|cuft/s|abbr=on}}

|Bering Sea

|

|

|

|Back River

|bgcolor="#6495ED"|{{convert|1150|km|mi|abbr=on}}

|

|

|Arctic Ocean

|

|

|

|Anadyr River

|bgcolor="#6495ED"|{{convert|1150|km|mi|abbr=on}}

|{{convert|191000|km2|mi2|abbr=on}}

|{{convert|2020|m3/s|cuft/s|abbr=on}}

|Gulf of Anadyr

|

|

|

|Liard River

|bgcolor="#6495ED"|{{convert|1115|km|mi|abbr=on}}

|{{convert|277100|km2|mi2|abbr=on}}

|{{convert|2434|m3/s|cuft/s|abbr=on}}

|Mackenzie River

|

|

|

|Yellowstone River

|bgcolor="#6495ED"|{{convert|1114|km|mi|abbr=on}}

|{{convert|181300|km2|mi2|abbr=on}}

|{{convert|380|m3/s|cuft/s|abbr=on}}

|Missouri River

|Longest undammed river in the contiguous United States.

|

|

|Maya River

|bgcolor="#6495ED"|{{convert|1053|km|mi|abbr=on}}

|{{convert|171000|km2|mi2|abbr=on}}

|{{convert|1180|m3/s|cuft/s|abbr=on}}

|Aldan River

|

|

|

|Fly River

|bgcolor="#6495ED"|{{convert|1050|km|mi|abbr=on}}

|{{convert|76000|km2|mi2|abbr=on}}

|{{convert|6500|m3/s|cuft/s|abbr=on}}

|Gulf of Papua

|Largest completely undammed river system in the world

|

|White River

|bgcolor="#00BFFF"|{{convert|934|km|mi|abbr=on}}

|{{convert|26000|km2|mi2|abbr=on}}

|{{convert|16|m3/s|cuft/s|abbr=on}}

|Missouri River

|

|Tanana River

|bgcolor="#00BFFF"|{{convert|916|km|mi|abbr=on}}

|{{convert|113960|km2|mi2|abbr=on}}

|{{convert|1172|m3/s|cuft/s|abbr=on}}

|Yukon River

|

|

|

|Thelon River

|bgcolor="#00BFFF"|{{convert|900|km|mi|abbr=on}}

|{{convert|142400|km2|mi2|abbr=on}}

|

|Hudson Bay

|

|

|

|Salmon River

|bgcolor="#00BFFF"|{{convert|684|km|mi|abbr=on}}

|{{convert|36000|km2|mi2|abbr=on}}

|{{convert|310|m3/s|cuft/s|abbr=on}}

|Snake River

|

|

|

|Stikine River

|bgcolor="#00BFFF"|{{convert|610|km|mi|abbr=on}}

|{{convert|52000|km2|mi2|abbr=on}}

|{{convert|1580|m3/s|cuft/s|abbr=on}}

|Pacific Ocean

|

|

|

|Skeena River

|bgcolor="#00BFFF"|{{convert|570|km|mi|abbr=on}}

|{{convert|54400|km2|mi2|abbr=on}}

|{{convert|1760|m3/s|cuft/s|abbr=on}}

|Pacific Ocean

|

|

|

|Susitna River

|bgcolor="#00BFFF"|{{convert|504|km|mi|abbr=on}}

|{{convert|52000|km2|mi2|abbr=on}}

|{{convert|1400|m3/s|cuft/s|abbr=on}}

|Pacific Ocean

|Alaska is planning to build a hydroelectric dam on the river at Devil's Canyon.

|

|