The National Park was declared on 1 April 2002 as an upgrade of the Protected Landscape Area (Slovak: Chránená krajinná oblasť (CHKO) Veľká Fatra) of the same name established in 1972 to protect a mountain range with a high percentage of well-preserved Carpathian forests, with prevailing European beech, which cover 90% of the area in combination with ridge-top cattle pastures dating back to the 15th – 17th centuries, to the times of the so-called Walachian colonisation.

In places there are also relict Scots pine forests and the Harmanec valley is notable as the richest Irish yew tree location in Central and probably all Europe.

NP Veľká Fatra is also an important reservoir of fresh water thanks to high rainfalls and low evaporation in the area.

Various rocks and therefore various soils, diverse type of terrain with gentle upland meadows and pastures, sharp cliffs and deep valleys provide for extremely rich flora and fauna.

All species of big Central European carnivores live abundantly there: brown bear, grey wolf and Eurasian lynx.