abstract-with the publication of Garret Hardin's "tragedy of commons" ,the developed world took a serious note on conservation and it culminated in the concept of sustainable development. However, we observe a total absence of the recognition of culture and human existance. It is predominantly guided by the philosophy of utilitarian development. It is not only observed in the development world, but also in less developed world, including countries like India, policy formulation to arrest environmental degradation has failed to address the livelihood issues of marginal communities like pastoraslists located in the high altitude of Western and Eastern Himalayas. As a result the term 'sustainable development' has become a misnomer, at least for those highland pastoralists In this paper ,an attempt has been made to study the transhumance activity (known as gothwala system) as a means of livelihood which is in existence in the mountain settlement in Lachung valley ,located in the east Himalayan State of Sikkim ,India and the role played by traditional local body of governance, the 'Dzumsa' towards managing the natural resources, especially forest and fodder,in a sustainable manner. It also shows a process of natural resource management which is not based on modern scientific knowledge but age old traditional knowledge of indigenous tribes. To a large extent , it works in conformity with the true essence of the definition of sustainable development which cautioned us that in the long run, human and natural systems can not economically be viable unless they are also ecologically sound and socially responsible. However, to protect the forest from extraction of firewood, save the medicinal plants from grazing of cattle, the Government of Sikkim has enacted a law to abolish the 'gothwala system' without providing any alternative livelihoods. In the next as well as in the concluding section, a critical evaluation has been made towards the conservation approach followed by formal institutions in the name of sustainable development and how a conflict has arisen between conservation and existing livelihood opportunities. keywords-transhumance, natural resource management, sustainable development, conservation, governance