White alder typically grows 30-75 feet high, with straight trunks are 1-2 feet thick. The branches start about halfway up the trunk. The edges of the 2-4 inch leaves curl slightly toward the under surface. Male catkins are 1-4 inches long, and are produced in clusters of 2-7. Pollination occurs in early spring, before the leaves emerge. The small winged seeds disperse through the winter, leaving the old, woody, blackish 'cones' on the tree for up to a year after.

White Alders grow naturally along river banks and canyon streams and are often planted as park trees. White Alder provides forage for many wildlife species. Mule deer eat its twigs, leaves, and buds, while American beavers use its bark for food and building dams and lodges.