Mountain Alder
Alnus incana ssp. tenuifolia

Family: Birch (Betulaceae)
AKA: Thinleaf Alder
Photo taken on: June 13, 2008
Location: Almont, CO
Life Zones: Foothills to subalpine
Habitat: Beside streams and lakes

Grows to 30ft, branched at base with smooth gray bark. Leaves are oval and have prominent veins. Flowers are catkins that appear before the leaves open.

Flora of North America reference.