Based on the actions made by Corporación Regional Yariguíes-GEAM, this article proposes an understanding of the environmental struggle against fracking developed by such group in Barrancabermeja (city of Santander, Colombia), from a perspective that encompass Structure of Political Opportunities, Discursive opportunities, Repertoire of contention and theories about Expertise and lay knowledge. The article concludes demonstrating that Political Opportunity demands the use of expert knowledge to be admitted in the land of environmental struggle and how this demand influences the repertoire of contention.
