Who uses the forage resources under a communal land tenure system? Using data from a Mexican Indian community with a history of communal land tenure extending prior to the Conquest, the research explores and attempts to answer this question. The analysis is based on 1970 socio-economic data for 533 households, secondary sources, and 1987 field observations in a community of Zapotec farmers in the State of Oaxaca, Mexico. The factors influencing who uses the communal resources include livestock ownership, wealth ranking, migration history, and participation in the local labor market. Although all members of the community have the right to graze animals on the commons, only a fraction of the wealthier households exercise this right. Consequently grazing pressure is minimized (reduced) compared to the potential grazing pressure that otherwise would be exerted if all the members of the community were to exercise their rights to use the forage resources at the same time.