Southern Patagonian Ice Field in the area, among which are the Upsala (765 km), Viedma (978 km) and Perito Moreno (258 km) in the Los Glaciares National Park in Argentina, and the Pío XI Glacier or Bruggen Glacier (1,265 km, the largest in area and longest in the southern hemisphere outside of Antarctica), O'Higgins (820 km), Grey (270 km) and Tyndall (331 km) in Chile. The glaciers going to the west flow into the fjords of the Patagonian channels of the Pacific Ocean; those going to the East flow into the Patagonian lakes Viedma and Argentino, and eventually, through the rivers "de la Leona"
Patagonian sheep farming boom sheep-herding areas along the Strait had been leased or reserved by 1884. The sheep farming boom altered not only the demographic and economic outlook of Southern Patagonia, but also changed the steppe ecosystem. Research suggests that sheep excrement might have caused eutrophication of lagoons like Potrok Aike, and sheep might also have caused considerable erosion. The Strait of Magellan and the Atlantic coast were covered by natural grasslands so no clearing of forests occurred during the introduction of sheep. Patagonian sheep farming boom In late 19th and early 20th centuries, sheep farming expanded across the Patagonian grasslands making the southern