551263 4134901 zone 17
In the mountain habitat garden near the yellow Buckeye tree. Full flower.
This is Rhododendron albiflorum, or White-flowered Rhododendron, which I've only seen twice before. It was growing on the Klahane Ridge trail and conveniently labelled by park rangers.
Common in understory. Most plants were just past peak bloom
in what was left of creek bed, alone Forest Dr. about mile east of Wawona Hotel. Flowers way past prime but still identifiable