The Rincon Mountains are a significant mountain range east of Tucson, Pima County, Arizona, in the United States. The Rincon Mountains are one of five mountain ranges surrounding the Tucson valley. The other ranges include the most prominent, the Santa Catalina Mountains to the north, the Santa Rita Mountains to the south, the Tucson Mountains to the west, and the Tortolita Mountains to the northwest. Redington Pass separates the Rincon Mountains from the Santa Catalina Mountains. The Rincon Mountains are generally less rugged than the Santa Catalina Mountains and Santa Rita Mountains. The Rincon Mountains are also included in the Madrean sky island mountain ranges of southeast Arizona, extreme southwest New Mexico, and northern Sonora Mexico.