This paper provides novel causal evidence on the long-run effects of private property on the sustainability of agricultural landscapes in the developing world. We leverage a natural experiment in Southern Chile where indigenous reservations under community-based tenure had differential access to a titling program depending on the court to which they were assigned. Using a Geographic Regression Discontinuity Design at the courts’ jurisdictional boundary, we show that private property increased the area of native forests, decreased the density of livestock, increased the area sown with oats, and possibly accelerated the demographic transition. These results are consistent with privatization bringing an end to a regime of open access to forest resources and grazing lands, forcing indigenous farmers to grow their own fodder and restrict livestock production. This narrative seems plausible given the process of forced settlement faced by these indigenous people, which did not facilitate the emergence of the institutions required to successfully manage access to forest resources.