“Collaborative governance has become a common theme in the literatures on environmental policy and the impacts of public administration and management on environmental governance. Research has addressed the structures and dynamics of effective collaboration and the perceived costs and benefits of this approach. However, a significant knowledge gap persists regarding whether collaborative efforts lead to improved environmental outcomes and the potential of collaboration to address existing regulatory limits and constraints. Public policy scholars have studied the limitations of iconic statutes such as the Clean Air Act, the Clean Water Act. These regulations based on a command-and-control approach have been criticized for being inefficient, expensive, inflexible and often, inadequate in addressing complex policy problems. However, a systematic analysis of the limits and constraints of the US environmental regulatory framework has not been undertaken to a large extent in the existing literature on collaboration. Further, the literature is limited in explicitly testing whether collaborative governance approaches such as public voluntary environmental programs (VEPs) can address the constraints of environmental regulations. The paper offers a conceptual framework to describe a type of limits and constraints of the US environmental regulatory framework. The paper analyzes the Great Lakes Restoration Initiative (GLRI) — a public voluntary environmental program lead by the US Environmental Protection Agency (EPA), established in 2009 during the Obama Administration. Findings from the semi-structured interviews of GLRI participants and analysis of archival documents show that the GLRI has been largely a successful program in terms of achieving its objectives. The key characteristics that are attributed to its success are funding and bipartisan political support. The challenge of the GLRI, however, remains in terms of developing strong metrics to evaluate the outcomes of the GLRI and integrating climate change into its projects. The findings have important implications for practitioners, academics, and those interested in the evolving role of US federal agencies such as the EPA from being a regulator to a change agent developing creative solutions to address our contemporary environmental challenges.”