Spiraea betulifolia ssp. lucida
From Oregon Flora, Gardening with Natives:
Birch-leaved spirea is a low growing deciduous shrub in the rose family. Its lovely white to light pink flowers bloom in showy dense clusters at branch tips. The long stamens give the flowering clusters the appearance of soft powder puffs when in full bloom. The leaves are shiny and turn lovely reddish-orange in the fall. This shrub does well in full to partial sun and well-drained, even dry, soil and it is well suited to the hedgerow, shrub border, or butterfly garden.