UNESCO declared the Forest a Biosphere Reserve of the Atlantic Forest in 1992, and following this the State of Rio declared it in parts a State Park in 2001 - it was completed and subsequently the remaining areas were named State Parks in 2005 and 2013.

Unlike its more famous neighbors the Pedra Branca State Park and the Tijuca National Park, The Forest of Gericinó - Mendanha is the least known and visited, partly due to the diffulty of access from the city center and the beaches of Zona Sul.

However, the Forest is unique in the fact that it contains a number of volcanic geological structures including the Chimney Lamego and Nova Iguaçu Volcano as well as numerous hot springs and volcanic vents.