The Baja California Peninsula's rugged spine—the Peninsular Ranges—hosts a series of sky islands rising from desert and Mediterranean landscapes. The five highest summits are:
| Peak | Elevation (ft) | Elevation (m) | Range / Notes |
|---|---|---|---|
| Picacho del Diablo | 10,479 | 3,194 | Sierra de San Pedro Mártir – Highest point on the peninsula |
| Volcán La Encantada | 10,056 | 3,065 | Sierra de San Pedro Mártir – Dormant volcanic cone |
| Sierra San Pedro Mártir (general high country) | 8,625 | 2,629 | Core of the national park, observatory site |
| Sierra La Laguna | 6,745 | 2,056 | Southern cape – Tropical dry forest biosphere reserve |
| Sierra Juárez | 6,673 | 2,034 | Northern section – Pine-oak forests, near Mexicali |
These mountains capture Pacific moisture, creating "sky island" ecosystems with endemic species (e.g., San Pedro Mártir cypress, peninsular bighorn sheep). The Sierra de San Pedro Mártir National Park protects the highest cluster, hosting Mexico's National Astronomical Observatory. Sierra La Laguna, at the tropical tip, is a UNESCO biosphere reserve. All offer hiking, climbing, and biodiversity tourism far from the peninsula's better-known beach corridors.