Query: Where is Oro Valley?
Context: The expansive area northwest of the city limits is diverse, ranging from the rural communities of Catalina and parts of the town of Marana, the small suburb of Picture Rocks, the affluent town of Oro Valley in the western foothills of the Santa Catalina Mountains, and residential areas in the northeastern foothills of the Tucson Mountains. Continental Ranch (Marana), Dove Mountain (Marana), and Rancho Vistoso (Oro Valley) are all masterplanned communities located in the Northwest, where thousands of residents live.