The Little Rincon Mountains are a small range of mountains, lying to the east of the Rincon Mountains, at Tucson, of eastern Pima County, Arizona. The range is located in northwest Cochise County and is part of the western border of the San Pedro River and Valley, the major valley and river of western Cochise County. The river is northward flowing to meet the Gila River; its headwaters are south of the US-Mexico border in northern Sonora. A small part of the Little Rincon range's southwest lies in Pima County.