There are five sierras (or mountain chains) in the Dominican Republic: Sierra de Neiba, Sierra de Bahoruco, Cierra Martín García, Llamaza y Samaná.

Sierra de Neiba

The Sierra de Neiba continues in Haitian territory under the names Trou D'Eau and Cadena de Matheaux and is limited to the north as well as to the south by large tectonic faults. Its genesis dates back to the Oligocene period of the Cenozoic Era. The tectonic dynamic from previous periods separated the Sierra from the Sierra Martín García. It has mostly calcareous or saltpeter rocks, creating a karstic relief. The predominant inhabitable regions, with little difference between their areas, are the Wet Forest Low Mountain habitat and the very Wet Forest Low Mountain habitat.

Sierra de Bahoruco

The Sierra de Bahoruco continues into Haiti, where it is named Massif de la Selle, and has altitudes that reach 2,367 m. Its genesis dates to the Oligocene period of the Cenozoic Era when its first relief was formed. It presents a geomorphology of steep edges and flat valleys: the Aceitillar Basin is in the highest part of the sierra and is of Polje origin (karstic depression caused by lateral and tectonic widening). Sedimentary rocks of caliche origin are most common, creating a karstic relief much like that of the Sierra de Neiba. The predominant habitat is very Wet Forest-Low Mountain.

Other sierras

The Sierra Martín García, Sierra Llamaza and Sierra Samaná are systems of moderate altitude and in them, the greatest quantity of extractable minerals are found, like gold and silver nugget in Yamasá and marble in Samaná.