This paper examines the nexus between new technology for an open access land resource and an institutional set-up for establishing and manging tree plantations as a common pool resource. For the Vankars, a scheduled caste of a coastal saline region of Gujarat, this meant a struggle at several levels in society. This land is owned by the state government. It is open access land managed by the village panchayat. The Vankars combined their knowledge of local resources with the techno-managerial inputs of an external non-government organization to evolve a new technology for making these lands productive. Some land was acquired from the Government on long lease on an individual basis and some on a group basis. In either case the Vankars soon realised that reclamation and management of such degraded lands called for pooling of the land as well as other resources. The paper examines the evolution of rules for using usufruct, providing labour and protection, processing wood into charcoal and marketing, in three cooperatives. These have been selected on the basis of land productivity as criterion. The mechanisms for sharing the set-up and maintenance costs of the plantations, the problems of fostering unity and the perceived stream of benefits realised by the members vis-à-vis the NGO are summarised. Implications are then drawn for building institutions around common pool resources.