Birding Basics

Colorado's Ecosystems

In 1991, The Denver Museum of Natural History developed a simple yet accurate approach to classifying Colorado's ecosystems. The eight ecosystems have familiar, descriptive names and reflect the realities of nature and of Colorado's topography.

Grasslands
The prairie grassland found east of the mountains is semi-arid. It's a land of perennial grasses, shrubs, and forbs, with trees found along waterways. About 40% of Colorado was once grassland. Now, most grassland is in agricultural use. »Read More

Riparian
Riparian habitats (wetlands) are found along rivers, streams, ponds, and water sources from the plains to the alpine tundra. They include cattail marshes, streamside cottonwood groves, willow thickets, and much more. Nearly 75% of wildlife depends, to some degree, on wetlands. »Read More

Semidesert Shrubland
Found primarily on Colorado's Western Slope, this arid, rough country of dry washes and low shrubs is dominated by big sagebrush. »Read More

Pinyon-Juniper Woodland
These pygmy forests are found in the foothills and in open, rolling, semi-arid country on rocky mesa tops and along canyon rims. Pinyon-Juniper woodlands may be mixed with montane shrublands and open areas of grasses and forbs. »Read More

Montane Shrubland
The transition zone of the Front Range foothills link the grasslands to the mountains. It is open country of Gambel oak and mountain mahogany. »Read More

Montane Forest
This zone is dominated by pondersa pine on dry, south facing slopes and Douglas-fir on moist, cooler, north-facing slopes. Aspen grow in areas of fire, avalanche, or other previous disturbance. »Read More

Subalpine Forest
These thick, moist forest of subalpine fir and Engelmann spruce, where deep snow persists into summer, extend to timberline. Lodgepole pine and aspen grow at lower edges, with gnarled limber and bristlecone pines in upper areas and along exposed ridges. »Read More

Alpine Tundra
The tundra is a treeless land of low-growing shrubs and plants punctuated by boulder fields, rock gardens, and talus slopes. The harsh nature of life at this altitude is belied each summer by the spectacular blooming of alpine wildlflowers. »Read More