Río Gallegos is the capital and largest settlement of the Patagonian province of Santa Cruz in Argentina. Located in the department of Güer Aike, it has a population of about 98,000, according to the 2010 census, a 24% increase from the 79,000 in the 2001 census. The city bears the name of the Gallegos River, and sits on its estuary 2,636 km south from the Argentine federal capital Buenos Aires.