Plants cespitose, not rhizomatous. Culms 20-35(50) cm, ascending to erect; nodes concealed. Ligules 0.5-1 mm, erose to ciliate; blades 2.5-5 mm wide. Spikes 4.5-7 cm; internodes 4-6 mm, ciliate, distal cilia longest. Glumes densely hairy, hairs 0.2-0.5 mm, apices mucronate or awned, awns to 1 mm; lemmas densely hairy, hairs 0.2-0.5 mm, apices awned, awns 1-5 mm, straight. 2n = 28.
Elymus alaskanus subsp. hyperarcticus grows on river banks and hillsides. It extends from the Lake Taymyr Basin in Arctic Russia across northern North America to Greenland.