Calochortus uniflorus

About

Calochortus uniflorus is a species of flowering plant in the lily family known by the common names Monterey mariposa lily and large-flowered star-tulip. It is native to western Oregon and to California as far south as San Luis Obispo County. It grows in moist areas, such as meadows, in coastal hills and lower-elevation mountains. Most of the populations are found in the Coast Ranges, but some occur in the Cascades and in the foothills of the Sierra Nevada.

Summary from Wikipedia