It is located in the Pampa de Junin or Meseta de Bombón (Junin Plain or Bombon Plateau), 13 451,44 feet above sea level, and has a surface area of 53 000 hectares. This reserve is situated in the departments of Junin (Carhuamayo, Ondores, and Junin districts, in the province of Junin), and Pasco (Ninacaca and Vicco districts, in the province of Cerro de Pasco). The lake Junin, also known as Chinchaycocha, takes up the largest area of the Reserve, and the settlers living on the riversides take advantage of its natural resources: birds and their eggs, frogs, and the cattail, etc.The lake Junin is characterized for its great diversity of birds, such as the Junin grebes (Podiceps taczanowskii), one of the most important species in the lake because it is endemic and in danger of extinction.
There are other 36 species which are representative of the Andean region, such as the speckled Andean teal (Anas flavirostris), the yellow-billed pintail (Anas georgica), the Puna teal (Anas puna), the Andean goose (Chloephaga melanoptera), the cattle egret (Bubulcus ibis), the common moorhen (Gallinula chloropus), the Andean gull (Larus serranus), the black-crowned Night-heron (Nycticorax nycticorax), the Chilean flamingo (Phoenicopterus chilensis), the Puna ibis (Plegadis ridgwayi), and the Silvery grebe (Podiceps occipitalis).The most common mammal in the Junin National Reserve is the wild guinea pig (Cavia tschuddii), which lives on islets of cattail and is the only guinea pig species in the Reserve. Other important species of mammals that can be found on rocky outcrops are the Andean fox (Pseudalopex culpaeus), the hog-nosed skunk (Conepatus chinga), and the Peruvian mountain vizcacha (Lagidium peruanum). Moreover, the lake Junin has populations of frogs very appreciated for their meat, such as the Batrachophrynus macrostomus and the brachydactylus. Other species of frogs, such as the Peruvian gastrotheca, the Pleaurodema marmorata, and toads (Bufo spinulous) can be found along the lake shore. Among the fish we have the Orestias elegans and O. empyraeus, commonly known as challhua, and the Pigydium oroyae, which is a type of catfish.The lake and the adjacent areas show a variety of emergent and submerged plants, which make up unique vegetable formations.
The predominant vegetation is made up of shrubs of Poaceae, such as the clematis (Calamagrostis sp.), the Festuca sp. and the Stipa brachyphylla -commonly known as ichu. Other species are the totora or cattail (Juncus andicola), which form islets where we can find species such as the giant bulrush and tule (Scirpus californicus), known by their native names mirmo or cheuga. The main objectives of the Junin National Reserve are to preserve the flora, fauna, and the beautiful landscape of the lake Junin and its surrounding areas; as well as to promote the rational use of its birds, frogs, and Andean cattail.