| Sagavanirktok River | |
| Map Size: | 300 |
| Pushpin Map: | USA Alaska |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Sagavanirktok River in Alaska |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Alaska |
| Subdivision Type4: | Borough |
| Subdivision Name4: | North Slope |
| Length: | 180miles[1] |
| Discharge1 Avg: | 4700cuft/s |
| Source1: | Between the Endicott and Philip Smith mountains |
| Source1 Location: | Brooks Range |
| Source1 Coordinates: | 68.1633°N -148.9314°W[2] |
| Source1 Elevation: | 4986feet[3] |
| Mouth: | Slightly northeast of Prudhoe Bay |
| Mouth Location: | Beaufort Sea |
| Mouth Coordinates: | 70.3208°N -148.0361°W |
| Mouth Elevation: | 0feet |
| Basin Size: | 5750sqmi[4] |
The Sagavanirktok River or Sag River (Iñupiaq: Saġvaaniqtuuq) is a stream in the North Slope Borough of the U.S. state of Alaska.[2] It is about 180miles long and originates on the north slope of the Brooks Range, flowing north to the Beaufort Sea near Prudhoe Bay. The Trans-Alaska Pipeline System and Dalton Highway roughly parallel it from Atigun Pass to Deadhorse.[5]
A glaciation happened approximately at the same time as the Illinoian Stage of central North America at the Sagavanirktok River.