Creeping Devil (Stenocereus eruca) - Foreground - and other cactus in the Baja Desert near La Paz. The Baja California desert is a desert ecoregion of Mexico's Baja California Peninsula. The ecoregion covers 30,000 square miles, and includes most of the Peninsula's western slope. It is bounded on the west by the Pacific Ocean and on the east by the Peninsular Ranges. The southern tip of the peninsula lies within the San Lucan xeric scrub ecoregion. The ecoregion is mostly covered by xeric shrubs, which create varying associations based on elevation and soil conditions. The ecoregion has close to 500 species of vascular plants. The climate is dry and subtropical. Although rainfall is low, the Pacific Ocean provides some humidity and moderates the temperature compared to the Sonoran desert, which lies on the east slope of the Peninsular Ranges.