Florida Wetlands on the San Simon River, Hidalgo County, New Mexico Not to be confused with Cienega of San Simon. San Simon Cienaga, a cienega, on the San Simon River in Hidalgo County, New Mexico.[1] References ^ U.S. Geological Survey Geographic Names Information System: San Simon Cienega 32°03′03″N 109°2′15″W / 32.05083°N 109.03750°W / 32.05083; -109.03750