Perennials, 15-35 cm; taprooted, caudex branches relatively thick, retaining old leaf bases. Stems erect, glabrous, eglandular. Leaves basal (usually persistent) and cauline; basal blades linear to linear-oblanceolate, (30-)60-110 × 2-4 mm, cauline gradually reduced distally, margins entire, faces glabrous, eglandular. Heads 1(-3). Involucres 3-3.5 × 5-6 mm. Phyllaries in 2-3 series, glabrous, minutely glandular. Ray florets 11-15; corollas white, drying lilac, often with an abaxial midstripe, 8-9 mm, laminae not coiling or reflexing. Disc corollas 2.1-2.5 mm. Cypselae 1.5-2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12-15 bristles. 2n = 18.

Flowering May-Jun. Crevices and ledges of steep, northfacing, lower cliffs (gneiss and schist); 1000-1200 m; Idaho.

Erigeron salmonensis is known only in the Salmon River Canyon.