The Flora of Mount Rainier -- a Photographic Journey, by Susan McDougall
Cascade Oregon Grape - Berberis nervosa
Very common in the understory of mature forests below about 3000 feet, tolerant of dark conditions. Photographed at Sunshine Point, in flower on May 18, 2014, and in fruit on August 25, 2014; in flower with a bee on May 8, 2017.