These are examples of Lewisii tweedyi, with text from an article at www.wenatcheeoutdoors.com by my friend Marc Dilley. Wenatchee Outdoors has a list of other articles here.
A gentle belle--resplendent in a muted setting of sharp needles, gritty soil and cold stone--Tweedy’s Lewisia clings to life in the least likely of environments.
Valued by many experts as the world’s premier rock garden plant, L. tweedyi is unique to impoverished, rocky settings in Wenatchee and Methow subranges of the Washington Cascades and in Manning Park, British Columbia. It was named after Frank Tweedy, a U.S. Geological Survey botanical collector who made the first ascent of Mt. Stuart on August 5, 1883. Much of L. tweedyi’s renown is due to its extravagant bloom.
A large flowering specimen can be spotted hundreds of feet away, its mass of flowers lighting the way like a beacon. While flowers are typically two to 10 per plant, individuals with 50 to 100 blooms are not uncommon.
Flowers in all stages of development may coexist on these large specimens.