The Sierra de la Laguna has been called an ”island in the sky” because of its topography which isolates it from the surrounding deserts. The Tropic of Cancer runs directly across the Cape and the Sierra de la Laguna at 23.5 degree latitude. Temperatures average highs of 74F in January and 88F in August. The area receives an average of almost forty inches of rain per year on the peaks — more rainfall than any other part of Baja, except the Californian region to the northeast. This moisture gives support to several unique ecosystems, a rare mix of desert,  sub-tropical, tropical, and sub-alpine species that may be found together nowhere else in North America. The highest elevations of the Sierra de la Laguna are blanketed in pine-oak forests, merging with tropical dry forest at about 750 meters in elevation.

Because the Sierra de la Laguna dry forests ecoregion was once a completely isolated island, hosting a large number of endemic species, after sufficient mountain uplift and over time joining the Baja Peninsula mainland, this ecoregion underwent significant speciation, and is thus today high in species diversity.

Because the ice age receded in such a way that most species were forced south, many species are unique to this area. Thus, not only was this area once an island, but, within the Cape Region, the Sierra de la Laguna now resembles an island from a species perspective, since there are so many unique ones, and since either oceans or weather cut it off from everything else.

The Sierra de la Laguna is the main high mountain range in the arid state of Baja California Sur, Mexico. It is high and narrow, rising boldly from coastal lowlands, with many precipitous and rocky slopes. Its peaks reach past 7200 feet. Above 5000 feet the mountains are occupied by the only woodland community for many hundreds of kilometers. Because of the receptive high altitude of the range, plant communities on the top have been historically less arid than those on the lowlands, and as such this unique environment has permitted the establishment of an amazing set of woodlands.

The oak and oak-pine woodland communities that occurs in such elevations contains a relative high proportions of both endemic and disjunct taxonomies, some quite exotic and beautiful.

(c) WWF

The Sierra ecoregion is contained in a larger geographic unit known as the Cape Region, and constitutes the southernmost part of the Baja California peninsula. As has been noted, the area is considered an island of vegetation due to its particular origin as an isolated land area, ten million years ago (during the Miocene), which later rejoined the more desert-like peninsula, as the last ice age came to an end.

The Sierra de la Laguna is rugged! The region is shaped by a vast complex of granitic mountains, running southward from the Gulf of California to the Pacific. It is composed totally of these massive intrusive rocks, with little else above or below ground besides these dramatic and rocky granites.

It is an extension of a great batholith of upperjurasic or lower cretaceous age, which underlies most of the peninsula and presumably also parts of the Gulf of California. Most of these rocks are moderately coarse grained and subject to rapid disintegration. The derivated soil is sandy, with a thin layer of litter; the content of loam and clay is relatively low. On slopes, foothills, and alluvial plains there are no differentiated soil layers. At the bottom of brooks and canyons. Some permanent pools occur on the hard rock bed.

The mountains are dissected by valleys and canyons, and surrounded by vast plateaus. The topographical features and geological events that gave rise to The Cape Region are responsible for the diversity of climates and of vegetation in this area.

High up in the Sierra the lay of the land changes considerably. And it keeps changing. Here are a few of the views from my most recent last trip: