Collaborative governance involves convening of government and non-government actors in policy formulation and implementation. Motivating collaborative governance is the expectation that engagement of diverse arrays of stakeholders in the public policy process allows policymakers and administrators to draw on the expertise, resources, and perspectives of these stakeholders to develop more contextually appropriate and effective policies. Since collaborative governance is fundamentally premised on the representation of diverse stakeholders in collaborative processes, assessing the extent to which representation is actualized is paramount. This paper adds to recent scholarship that examines representation dynamics in collaborative governance arrangements, focusing specifically on: (i) how diverse stakeholders included in collaborative governance arrangements are descriptively and substantively represented; (ii) how substantively represented stakeholders are coordinating on informational and relationship building activities; (iii) how representation and coordination dynamics change over time; and (iv) the extent to which representation and coordination dynamics are indicative of collaboration life cycle stage. Additionally, in responding to this latter aim, the paper presents a novel approach for measuring life cycle stages. The paper reports on a comparative case study of environmental justice councils, which are collaborative governance arrangements convened by states to assist in the design and implementation of policies aimed at reducing environmental harms within low income and minority populated communities.