The magnifient Colorado blue spruce (Picea pungens) was designated the official state tree of Colorado in 1939. Known for its stately, majestic, symmetrical form and its beautiful silver-blue color, the Colorado blue spruce was first discovered on Pikes Peak in 1862 by botanist C.C. Parry , and named by George Engelmann in 1879. Blue spruce (Picea pungens Engelm) is also the state tree of Utah.

Colorado school children voted to name the blue spruce as the state tree on Arbor Day in 1892, however it was not until 1939 that the Colorado blue spruce was officially adopted as the tree symbol of Colorado (see all state trees).

Sometimes called the silver spruce, the Colorado blue spruce ranges in color from green to blue to silver. In Colorado, it grows in small, scattered groves or singly among ponderosa pine, Douglas fir, alpine fir and Englemann spruce.

Source:

State Tree: Colorado State Archives - Symbols & Emblems
Colorado Blue & Engelmann Spruce: SW CO Wildflowers

Links:

Blue Spruce: Bellarmine University
Colorado blue spruce: Penn State Mont Alto
The Trees of Rocky: Colorado Guide
Colorado Blue Spruce: Northern State University
Mixed-conifer forests - Colorado Plateau: CP-LUHNA
National Christmas Tree: Train Web
Colorado Blue Spruce: Arboretum at Penn State Behrend
Pine cone photo: Camelotnorth photo gallery 1
Colorado Blue Spruce images: Forest View Evergreen Farm
State Trees - 50 States List