| Cosna River | |
| Map Size: | 300 |
| Pushpin Map: | USA Alaska |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Cosna River in Alaska |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Alaska |
| Subdivision Type4: | District |
| Subdivision Name4: | Yukon - Koyukuk Census Area |
| Length: | 44miles[1] |
| Source1: | Bitzshtini Mountains |
| Source1 Coordinates: | 64.4094°N -152.0086°W[2] |
| Source1 Elevation: | 1985feet[3] |
| Mouth: | Tanana River |
| Mouth Location: | 32miles northeast of Bitzshtini Mountains |
| Mouth Coordinates: | 64.8544°N -151.3653°W |
| Mouth Elevation: | 249feet |
The Cosna River (Lower Tanana: K'osno) is a 44miles tributary of the Tanana River in the central part of the U.S. state of Alaska.[1] It flows northward from the Bitzshtini Mountains into the Tanana west (downstream) of Manley Hot Springs.[4]
In 1899, Lieutenant J. S. Herron attributed the name to the Tanana peoples living in the area.[2] However, a century later linguist William Bright, citing the Koyukon Athabascan Dictionary, attributed the name to the Koyukon words kk' os, schist rock, combined with no, river.[5]