The American photographer Alex Prager grew up in the 1980s in Los Angeles, where she became enamored with the Old Hollywood aesthetic. After dropping out of school, she saw an exhibition of photographs by William Eggelston, whose mysterious color portraits and still lifes captured the magic within the mundane. Prager began taking pictures, and six months later she had her first show. Now 42, Prager often uses trained actors in staged settings, inviting viewers to “complete the story.” In “Part One: The Mountain,” a series of portraits evokes a metaphorical Americana of turmoil and desire. —E.C.