Some of the inhabitants of the steppe,such as the guanaco (Patagonian Llama) run quickly amongst the scattered shrubs and rounded bushes, while others, such as the piche (Armadillo), move along slowly. The lakes and lagoons, in which these landscapes are reflected, are also the meeting place of diverse species of wild fowl which are renewed with the changeing of the seasons.

Today, these glaciers only occupy the peak of the Tronador mountain where the winter snow falls become compact creating a hard bluish, crystaline mass.   Ten glaciers slide down from the summit and slowly mould the landscape.   We can observe them at work when visiting the Ventisquero Negro (Black Blizzard).

The Tronador (Thunderous), called Anon by the indigenous people, is 3.478 meters high and is the highest peak in the Nahuel Huapi National Park.   Its present name alludes to the constant rock and ice falls, and the noise made by its blocks of ice which are in permanent movement.

In around 1870, an expedition leaves Chile to explore the shores of lake Llanquihue, and on the way discovers the mouth of the river Manso, "...which we named Manso (Docile) because of its calm waters."   Little did they know that this tranquil river is also the swift torrent that winds its way accross wide valleys or squeezes its way through the narrow gorges, which often provoke rapids and waterfalls.

The river Manso has its source in the Manso, Castano Overo and Alerces glaciers, situated on the eastern slopes of the Tronador maountain. Over a distance of 100 kms.this plentiful river unites lakes Mascardi, Los Moscos, Hess, Roca, Steffen and Martin.   These, together with the environments through which the river passes, constitute the Manso hydrographical basin; one of five protected by this park.

An imaginary line (in a NO - SE direction) between lakes Mascardi and
Gutierrez separates two hydrographical basins.   Starting from this line, water from rivers and streams collected by lakes Gutierrez and Nahuel Huapi flow into the Atlantic ocean by way of the river Limay, and form part of the Nahuel Huapi Basin.   And water from lake Mascardi, following a shorter route via the river Manso, drains into the Pacific forming the Manso basin.  A delicate balance between the quantity of water from the snow and rain which falls in the region and that which is absorbed and distributed by the woods, is what regulates the flow of a basin.   Not only the supply for drinking water and for crops and
forestation depends on this essential process, but also the water supply for a great part of the hydroelectric energy which is consumed in the country.

Una Successively lost and found, that seems to have been the destiny of the Vuriloche pass.  An ancient path that, making its way through the dense valdivian forest and over steep hills, connects Chile with Argentina. Situated to the south of the Tronador mountain, this track was used by the indigenous people that lived on both sides of the andes for the interchange of products.

In time it fell into disuse and its route was forgotten.   The jesuit missionaries were very interested in finding it, as they envisaged this path as being a quick way to get from Chile to the evangelical mission on the shores of lake Nahuel Huapi.   Around 1700, the father Guillermo finds the historic pass, but is unable to cover its whole length as he died on the way.

Again the pass was to be forgotten until the 19th century, when the possibility of a commercial connection between the Chiloe region in southern Chile and the Nahuel Huapi region, prompted a fresh search. Towards 1880, Dr. Francisco P. Moreno finds the argentine end of the pass in an exploratory journey in the region.   The crossing of this pass is today one of the attractions that this zone of the park offers the tourist.