Successive glaciations have molded the landscape in the region creating spectacular features such as moraines, glacial cirques and clear-water lakes.

The vegetation is dominated by dense temperate forests, which give way to alpine meadows higher up under the rocky Andean peaks.

The property is vital for the protection of some of the last portions of continuous Patagonian Forest in an almost pristine state and is the habitat for a number of endemic and threatened species of flora and fauna.

[1] Designated a World Heritage Site in 2017, the park was created in 1937 to protect forests of alerce trees, called lahuán by the Mapuche people, and other examples of the flora of the Patagonian Andes.

The alerce is restricted to a small range in Chile and Argentina and the species is endangered due to exploitation of the tree for lumber.

Taller and larger alerce trees are believed to exist on the southwestern arm of Lake Menéndez, but access to that area is restricted.

[6] The highest point in the Los Alerces National Park is Cordon de las Pirámides, 2,440 metres (8,010 ft) in elevation.

Eastward from the crest of the Andes, in a rain shadow, precipitation decreases rapidly, falling to about 800 millimetres (31 in) at the eastern edge of the park.

In the west of the park, there is high rainfall and Valdivian temperate rain forests below the higher elevations of the Andes.

[12] A hydroelectric dam, providing energy to industry in Puerto Madryn, has created the large Amutui Quimey Reservoir, which empties into the Futaleufú River which flows on to Chile.