Rio Grande (New Mexico) The Rio Grande flows out of the snowcapped Rocky Mountains in Colorado and journeys 1,900 miles to the Gulf of Mexico It passes through the 800foot chasms of the Rio Grande Gorge, a wild and remote area of northern New Mexico The Rio Grande and Red River designation was among the original eight rivers designated byThe river reach considered the Upper Rio Grande in New Mexico runs from the ColoradoNew Mexico state line to the Otowi gage located near State Highway 4 and San Ildefonso Pueblo Upper Rio Grande tributaries include the Red River, Rio Hondo, Pueblo de Taos, Embudo Creek and the largest tributary, the Rio ChamaTwo 300footlong approach spans with a 600footlong main center span The bridge was dedicated on and is a part of US Route 64, a New Mexico Real Time Water Measurement Information System Map rio grande river new mexico