Plants densely cespitose. Culms with angles smooth proximally, 17-70 cm. Leaves: sheaths adaxially white-hyaline, often tinged brown distally, summit usually U-shaped, sometimes prolonged to 1.5 mm beyond collar; distal ligules 0.5-1.5(-3) mm; blades (2-)3-4 per fertile culm, 8-20 cm × 2.2-3.8 mm. Inflorescences dense, dark or chestnut brown or brown and green (gold), 1.2-2(-2.5) cm × 8-15 mm; proximal internode 1-3(-4) mm; 2d internode 0.5-3 mm; proximal bracts usually bristlelike, shorter than inflorescences. Spikes 5-9(-12), densely aggregated, individually indistinct, ovoid or broadly ovoid, 7.5-11 × 3.5-6.5 mm, base rounded to attenuate, apex truncate to tapered. Pistillate scales gold to brown, with pale to gold midstripe, lanceolate to ovate, 3.1-3.8 mm, shorter than and narrower than or as wide as perigynia, margin usually not white, apex obtuse to long-acute. Perigynia appressed-ascending to ascending, green to straw colored, conspicuously 6-8-veined abaxially, conspicuously 3-4(-6)-veined adaxially, at least 3 veins longer than achene, narrowly lanceolate to lanceolate, biconvex, 4-5.1 × 1-1.3(-1.5) mm, (0.4-)0.5-0.55 mm thick, margin flat, including wing 0.1-0.25 mm wide, ciliate-serrulate at least on distal body, pithlike tissue usually present in proximal perigynium walls; beak usually dark brown at tip, cylindric, unwinged, ± entire for 0.5-0.9 mm, abaxial suture inconspicuous or with white margin, distance from beak tip to achene 2.2-3.1 mm. Achenes narrowly elliptic to oblong, (1.1-)1.4-1.8 × 0.6-0.9 mm, 0.3-0.5 mm thick.

Fruiting late summer. Open rocky places, coniferous woods; 2400-2900 m; Colo., Mont., Utah, Wyo.