Betula occidentalis: Water Birch, Western Water Birch, Western River Birch, Red Birch, Western Red Birch, Black Birch, Spring Birch, Mountain Birch, Rocky Mountain birch. A multi-trunked small tree 15-20' tall. Most often found growing very near water and within seasonal flood zones. Very tolerant of heavy snows and frequent avalanches. Most often with rich reddish or coppery bark but often with white bark as trunks mature. Fall colors vary from clear yellow through rich gold and into reddish-purple. The Villager collects seeds from specimens at high elevations in the southern Sierra's eastern slope. This species readily hybridizes with B. papyifera (Paper Birch) in the north west and may also cross with B. nana, B. glandulosa, B. pumila,
B. neoalaskana, where their ranges overlap.