San Ildefonso Tultepec is a community of indigenous Otomis located in the southeastern corner of the state of Queretaro, Mexico. The terrain is rocky, the land mostly barren, the people striving to survive with their small corn and bean plantations.
Nine years ago, Sr. Mary came from the USA to live in San Ildefonso to direct a community-based program for women and children. During the summers she directed a two week summer camp for children, youth, and women. For the past five years they have used the Earth Charter as the basis for the classes.
More detailed information here. And presentations of how the Earth Charter was used here and here.