Deschampsia elongata is widely distributed throughout both American continents. In western North America, the species range extends from California north to Alaska, includes southwestern Canada and Nunavut, and extends eastward to Wyoming and New Mexico. In South America the range includes portions of Argentina, Chile, Peru, Bolivia and Uruguay. Tolerant of moist soils California oatgrass is found on coastal prairies, outer coastal mountain ranges, wet meadows and moist open forest soils; however it is also widespread on certain well-drained arid soils including some desert grasslands.
Commonly known as California oatgrass, this tufted species can attain a height of 80 centimeters, and exhibits two to five spikelets per individual. The bluish green cylindrical culms are hard, but also succulent in texture. This grass provides excellent forage for both wild ungulates and livestock.