Plants perennial; not rhizomatous. Culms 50–100 cm, erect; nodes 2–3(4), glabrous, internodes glabrous or puberulent just below the nodes. Sheaths glabrous; auricles absent; ligules to 1 mm, glabrous, truncate; blades (8)12–19(24) cm long, 4–8(14) mm wide, flat, glabrous, margins scabrous. Panicles 6–14 cm, erect, contracted; branches erect or ascending. Spikelets 15–30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (3)5–7 florets. Glumes glabrous or sparsely pubescent; lower glumes 7–11 mm, 1(3)-veined; upper glumes 9–12 mm, 3-veined; lemmas 12–15 mm, elliptic, rounded over the midvein, backs and margins pubescent or nearly glabrous, apices obtuse, entire; awns 2–5 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2–3.5 mm. 2n = 14.
Bromus suksdorfii grows on open slopes and in open subalpine forests, at about 1300–3300 m, from southern Washington to southern California.