Festuca altaica is a common and abundant tufted grass (sometimes forming tussocks) that occurs across Denali from the lowlands to the alpine zone, but is most common in the mountains. It occurs in numerous habitats in Denali from dry woodlands to alpine meadows and tundra on both sides of the Alaska Range crest. Festuca altaica has a loose panicle of spikelets. Flowering stalks can reach up to 70 cm high from fibrous roots. Individuals often form large bunches, up to 25 to 50 cm in diameter. Basal sheaths are long-persistent, yellowish-brown. Leaves are mainly basal, folded, narrow, stiff and scabrous, up to 4 mm wide when flat. The inflorescence is an open panicle, roughly triangular in outline, with lax branches. Spikelets contain several bisexual flowers, 10-15 mm long. The two glumes are shorter than the florets. The lemmas are 5-nerved with short awns 0.2-0.7 mm long. Fruits are single-seeded, dry and indehiscent. This species can be separated from other fescues by its stature (relatively tall and stout), open panicle (as opposed to closed and spike like), narrow folded leaves, and short awns.

Festuca altaica is a perennial bunch grass that typically flowers mid-summer.

Festuca altaica is monoecious with bisexual florets. It is wind-pollinated and fruits are wind-dispersed. Grass species are typically self-incompatible. Seeds are gravity and wind dispersed. Plants sometimes spread vegetatively via rhizomes.

Festuca altaica has a wide ecological tolerance, and is found on a variety of soil types. Recorded habitat types include rocky slopes, moist and dry tundra, willow scrublands, forest edges and disturbed areas.

Wide-ranging, moist to dry sites across the landscape.