| Itkillik River | |
| Map Size: | 300 |
| Pushpin Map: | USA Alaska |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Itkillik River in Alaska |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Alaska |
| Subdivision Type4: | Borough |
| Subdivision Name4: | North Slope |
| Length: | 220miles[1] |
| Source1: | Endicott Mountains |
| Source1 Location: | Near Oolah Pass, Brooks Range |
| Source1 Coordinates: | 68.0883°N -150.0061°W[2] |
| Source1 Elevation: | 5276feet[3] |
| Mouth: | Colville River |
| Mouth Location: | 25miles southwest of Harrison Bay on the Beaufort Sea |
| Mouth Coordinates: | 70.15°N -150.9389°W |
| Mouth Elevation: | 7feet |
The Itkillik River is a 220miles tributary of the Colville River in the North Slope Borough of the U.S. state of Alaska.[1] The river flows northeast then northwest out of the Endicott Mountains near Oohlah Pass to meet the larger stream about 25miles southwest of Harrison Bay on the Beaufort Sea.[2] An Iñupiaq map, drawn in about 1900, identifies the river as It-kil-lik, meaning Indian.[1]
A melting permafrost formation exposed along the Itkillik River is the largest known yedoma in Alaska. The formation, deposited between 50,000 and 10,000 years ago, contains remains of bison, muskoxen, mammoths, and other animals embedded in an ice cliff that is 100feet high and 1200feet long. The ice is rich in methane. Odors emitted by the gasses released when the ice thaws have led to the site's nickname, the Stinking Hills or Stinky Bluffs.[4]