The Sierra Nevada range, which forms the western rim of the Basin, sends into the state a single lofty spur, the Washoe Mountains.
In the Washoe Mountains, as in the rest of the Sierra Nevada range, there is a heavy growth of conifers, extending down to the very valleys; but in many places these mountains have been almost deforested to provide timbers for the mines.
The rocks of Falcon are believed by Sievers to belong to the Andean system; while the outlying peninsula of Paraguana probably belongs, geologically, to the same massif as Goajira and the Sierra Nevada de Santa Maria in Colombia.
Similar rocks are also found in the Cordillera Negra, but the volcanic centres appear to have been in the Sierra Nevada.
It is built partly on the beach and partly on the slopes of the Sierra Nevada de Santa Marta towards the S.E.
