I work at a park (New Hogan Lake, in Valley Springs, CA), and our Information Center's flora display had the attached photo on a board that stated this plant was "Mariposa Lily". I have some doubts about this identity, but I'm no expert. It doesn't look like any Mariposa Lily in California based on my limited knowledge and from viewing photos online. Mariposa Lily photos I have seen online show just 3 petals, while this photo shows 5 petals. I'd like to know the genus and species names, if possible, so that I can properly label it. What is this plant?