This paper argues that participatory governance initiatives like co-management can be made effective through agency rulemaking. Using the Mackenzie Valley Environmental Impact Review Board as a case study, this paper affirms that it is possible for marginalized stakeholders to participate in co-management and alter decision-making. By using its formal authority to generate rules that reflect community perspectives, this board contextualized environmental assessment in community-based perspectives. The study of participation presented here illustrates: 1) that a high level of agency support for community participation in rule-making can lead to rules which reflect community perspectives; and 2) that agency implementation of community perspectives has led to the increased use of stakeholder collaboration through private agreement. Nonetheless, the paper also addresses limitations on the ability to translate social needs into privately negotiated agreements where negotiations depart from highly commoditized terms. Consequently, this paper questions the use of negotiated agreements to meet the goals of stakeholder participation, as conceived by deliberative democratic strands of new governance.