The Sierra Madre Occidental region, which encompasses northeastern Sonora in Mexico and borders the southern border of Arizona in the United States, is recognized worldwide as a center of biodiversity. It represents a key binational biological corridor for many native and migratory wildlife species, many of which are threatened or endangered. Mrs. Anna Valer Clark and her family, through her organization Cuenca de Los Ojos, A.C. (CLO, acronym in Spanish), have dedicated the last 40 years to restoring and protecting these extraordinary Mexican ecosystems. Thanks to her work, more than 53,000 hectares of native grassland and scrubland have been restored, and important wetlands have been recovered. This territory is conserved through nine properties under CLO stewardship in northeastern Sonora.

FMCN, CLO, and the Wyss Foundation have agreed to a partnership in which Wyss provides $10 million in equity to manage nine ADVC-certified properties. FMCN is in charge of the financial management of the endowment and channels annual returns that fund an Annual Operating Plan for the CLO properties. Annual returns from the endowment, contributed by the Wyss Foundation, are used to cover the costs of maintaining and managing the properties. At the same time, FMCN provides counterpart resources for grassland restoration, wildlife monitoring, fire management, research, and environmental education activities.