Sierra de San Francisco is located south from the border line that separates Baja California and Baja California Sur, between Guerrero Negro and San Ignacio at the northeast of the Federal Highway No. 1. This Sierra is part of the Mulege Municipality and El Vizcaino Biosphere Reserve.

The mountains of this Sierra are the northern part of ranges that run all along Baja California Sur. It is an irregular volcanic mountain range of approximately 1600 m (4800 ft) long, drained by steep canyons that provide proper conditions for groves and mesquite forests.


The region has dry desert weather; hot summers, cool and cold winters and an average temperature between 12°C and 25°C. Rain season is from July until November.

During winter (November to March) it is essential to take warm clothes and in the summer (June to September) temperature rises up to 37°C, therefore it is recommended to take light clothing, sun protection (sunscreen, hat, cap), and lots of water. The rest of the year (April, May, October) there is mild weather.