South of the U.S.-Mexico border in the state of Sonora, where the foothills of the Sierra Madre begin to climb skyward, the Northern Jaguar Reserve is situated in the heart of a 1,500-square-mile area identified as prime northern jaguar habitat. The 55,000-acre reserve occupies the majority of an inland peninsula framed by the Ríos Aros and Bavispe. The remarkable Río Aros is the last free-flowing river in northern Mexico and supports aquatic prey like fish and turtles, Neotropical river otters, the densest breeding population of common black-hawks known in Sonora, and the southernmost nesting bald eagles in North America.
The human population in the area is extremely low, with the closest town to the reserve being Sahuaripa 35 miles away and the nearest city Hermosillo 160 miles in the distance. The first inhabitants of Sahuaripa were the Opata (Sahuaripa means “yellow ant” in the Opata language). Today, cattle ranching is the foremost economic activity in the region. The population of Sahuaripa is estimated at 5,000 residents.