The park extends across the central Bolognese Apennines around two large reservoirs created in the early 1900s for hydroelectric power production. The extended ridge formed by Mount Calvi (1283 m a.s.l.) and Mount Stagno separates the valleys of the Brasimone and Limentra di Treppio Streams, the main tributaries of the two lakes. The slopes and sandstones of the main elevations along the western part of the mountain range and below the Brasimone reservoir, forming the stunning Cinghi delle Mogne, are almost completely covered in mixed forests of oak, beech and replanted conifers.