Río Gallegos is the capital and largest settlement of the Patagonian province of Santa Cruz in Argentina. Located in the department of Guer 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 Argentinian federal capital Buenos Aires.