Situated at 114 km from Mahajanga , The National Park and the forest Station are around Ampijoroa at an altitude comprised between 80 and 333m .
Area : The National Park and the forest Station : 65 520 ha. The forest Station of Ampijoroa : 20 000 ha approximately.
Ampijoroa comprises a valley situated westward Ankarafantsika .The eastern and southern edges of the reserve are abrupt and form cliffs. Many waterways flow northward and southward the plateau .
There are many lakes in Ankarafantsika such that adjacent to Ampijoroa forest station . The forest Station Lake northward the national road shelters some crocodiles .Swimming is forbidden . The site serves as water storage for the rice growing of Marovoay plain .

The annual pluviometry is from 1000 to 1500 mm. Strong precipitations in January. The dry Season spreads over May to October . Monthly average Temperatures between 17°C and 35°C.

The original forest occupies a great part of the reserve .It is dominated by the association of Dalbergia, Commiphora, Hildergadia , representative families are the Asteraceas , Myrtaceas , the Fabaceas and Apelidaceas . Several species that easily adapt to seasonal dry conditions are counted in this deciduous dense forest. The canopy height varies between 15 to 20 m in valleys and well watered zones , on sandy grounds of high areas it is 5 to 10 m . Many lianas in the dense stratum of schrub .

Hundred bird species , among which many Vangas species such the Van Dam Vanga specific to the region , rare species such the Mesitornis Variegata and the Haliaeetus Veciferoides.
15 species of mammals among which the rodent Macrotarsomys ingens , 2 species of tenrecs and 6 species of lemurs : the Propitheque of Verreaux , the Avahi Laniger Occidentalis , the Lemur Mongoz…… .
Among the 38 species of reptiles, specimens that have been only counted in the national park or the Forest Station, : the Pygomeles petteri , the Chamaeleo angeli . An endemic terrapin Erymnochelys madagscariensis can also be found there . A program led by the DURELL WILDLIFE TRUST PRESERVATION consists in breeding and preserving 2 endangered endemic tortoise species , the Kapidolo - Pyxis planicauda and the Géochelone yniphora .