Rancho El Uno

Conserving grasslands and species through regenerative ranching and grassland restoration

The Project

The project's objective is to conserve the grasslands and species that inhabit Rancho El Uno (ReU) through regenerative cattle ranching, low-stress bison handling, and grassland restoration.


ReU has operated as a nature reserve for the conservation of Chihuahuan desert grasslands for the past 15 years; it encompasses 18,546 hectares in the heart of the Janos Biosphere Reserve. ReU represents one of the most important sites on the continent for migratory birds and emblematic species, such as the American bison, the black-tailed prairie dog, and the golden eagle. ReU is a key piece in maintaining the functionality of the binational biological corridor that connects the Great Plains in the United States with the Mexican highlands.

Thanks to a large multi-institutional effort in Mexico, progress has been made in the recovery of the American bison (Bison bison) in the wild. In 2009, 23 bison were reintroduced into ReU from conservation herds in South Dakota, USA, and in 2018, when ReU went into FMCN stewardship, the herd numbered 230 individuals; today, it is 383, which requires correct handling to maintain the health and viability of the bison population. In November 2019, 19 bison were moved from ReU to the plains of Coahuila, in the El Carmen Natural Reserve, within the Maderas del Carmen Protected Area, in a coordinated effort between the National Commission of Protected Areas (CONANP, acronym in Spanish), the General Directorate of Wildlife of the Ministry of the Environment and Natural Resources (SEMARNAT, acronym in Spanish), CEMEX, AES Mexico and FMCN.

ReU is operated and managed by the Cuenca de Los Ojos organization (CLO), which has spent the last 40 years on the restoration and protection of Mexican grasslands in northeastern Sonora, in addition to having extensive experience in regenerative ranch management; an example of this is the nine properties under its custody in northeastern Sonora. The collaboration between CLO and FMCN for the conservation of ReU is formalized through a donation contract that is renewed every year.

The lines of work that guide ReU actions are:

  1. Ecosystem functionality for wildlife representative of the native grasslands of the Chihuahuan Desert.
  2. Synergy with local and national stakeholders for more effective management.
  3. Financial sustainability for the conservation of ReU.

ReU represents one of the continent's most important sites for migratory birds and iconic species, such as the American bison, black-tailed prairie dog and golden eagle.


ReU has a plan for prescribed burning to reduce flammable material and renew rusty grass. In addition to reducing fire risk, this activity helps increase the area of prairie dog colonies and maintain habitat for migratory grassland birds.

In the second half of 2023, CLO successfully carried out low-stress management of 367 bison using a new marking system that can be considered satisfactory two years after its implementation. Likewise, ReU maintained its commitment to being a center for projects related to grassland conservation and its ecosystem's characteristic fauna. The CLO team continues to work on developing a monitoring plan. It continues to be a central training point for students of various levels, offering the opportunity for educational visits and professional internships for students, particularly from the University of the State of Sonora and the Autonomous University of Chihuahua.

Learn more about the project:



      • The Nature Conservancy México