|Towns||Livermore, Harts Location|
|• elevation||2,680 ft (820 m)|
|827 ft (252 m)|
|Length||9.1 mi (14.6 km)|
The Sawyer River rises in the unincorporated township of Livermore, New Hampshire, on the eastern side of Hancock Notch, a pass in the Pemigewasset Wilderness between Mount Hancock to the north and Mount Huntington to the south. The river flows east, paralleled by the Hancock Notch Trail, into a broad valley with Mount Carrigain to the north and the smaller summit known as Greens Cliff to the south.
The river turns northeast, with Carrigain Brook joining from the north and the outlet of Sawyer Pond joining from the south, and enters a deeper, narrower mountain valley as it descends to Crawford Notch. The river is paralleled in this lower section by the Sawyer River Road, a gravel Forest Service access road open to the public May–October. The Sawyer River enters the town of Hart's Location and ends at the Saco River near its great bend to the east as it leaves Crawford Notch.