Large-scale emergency response requires management of collaborative networks that stretch across government agencies and levels, and that include nonprofit and private organizations. Management of such collaborative networks has been recognized as a research area in need of further study. Inter-organizational complexities associated with these collaborative networks give rise to unanticipated contingencies that compound issues directly associated with an emergency itself. Planning for such response is therefore intrinsically limited, and emergency managers must bridge the gaps via articulation practices in real-time. In this paper, the authors draw on empirical data to develop a conceptual framework characterizing dimensions of inter-organizational complexity and domains of response coordination through which emergency managers articulate large-scale response efforts. The framework is illustrated with examples of state-level emergency managers articulating threads of networked response efforts concurrently through vertical and horizontal dimensions of inter-organizational complexity, and logistical, jurisdictional and governance domains of coordination. Theoretical and practical implications are discussed.