The state is in an offshoot of the Sierra Madre Occidental mountain range and geographically consists of four mountain systems. The most important of these is the Cerro Grande and its related peaks of Jurípicho-Juluapan, Los Juanillos, La Astilla, El Ocote, El Peón, El Barrigón, San Diego, and La Media Luna. The second consists of mountain chains parallel to the coast between the Marabasco and Armería Rivers, which include El Espinazo del Diablo, El Escorpión, El Tigre, El Aguacate, El Centinela, El Tora and La Vaca. The third is located between the Armería and Salado Rivers and includes the Alcomún y Partida, San Miguel y Comala and San Gabriel/Callejones peaks. The last is between the Salado and Naranjo or Coahuayana Rivers and contains small mountain chains such as the Piscila, Volcancillos, La Palmera, El Camichín and Copales. Three quarters of the state is covered by mountains and hills.