Sierra de Vallejo

The Sierra de Vallejo is the steep, forested range that rises behind the Riviera Nayarit coast, filling the land between the valley of Bahía de Banderas to the south and Compostela to the north. Scientists put it at roughly 70,000 hectares in the municipalities of Bahía de Banderas and Compostela, stretching from about the latitude of Valle de Banderas north to beyond Rincón de Guayabitos. Geologically it continues the coastal mountains of Jalisco and forms part of the lower basin of the Ameca River. Its slopes are cut by deep ravines and a dense web of rivers and streams that water the farming valleys below.

Nayarit declared it a state biosphere reserve in 2004, and in January 2024 the federal government folded it into the much larger Sierra de Vallejo-Río Ameca Biosphere Reserve, about 225,000 hectares that also take in the Ameca valley and mountains in Puerto Vallarta, San Sebastián del Oeste, Mascota and Mixtlán in Jalisco. Conservationists, including the group Alianza Jaguar, campaigned for that protection for two decades, and researchers note that the decree still lacks a management plan.

Medium-height tropical forest covers most of the sierra, with dry forest on the southern slopes of Compostela, oak woods higher up and gallery forest along the rivers. It is one of the places in western Mexico where the jaguar still lives, along with the guacoyul palm, and a survey by the Universidad Autónoma de Nayarit counted 261 bird species, 31 of them found only in Mexico and 43 in some category of threat. Between about 200 and 1,200 meters, farmers grow coffee under the shade of the native trees, and these plantations turn out to be rich bird habitat. Farming, cattle and new tourist development are the main pressures on the forest.

There is no visitor center or park entrance. Most people see the sierra from the coast road or on a guided hike or ATV tour from Sayulita and the towns of the bay, such as the biologist-led walks in the private Natikari reserve near Sayulita.