Developing scenarios to explore possible environmental futures is a widely used tool in social-ecological research. Scenario planners working in environmental systems increasingly enlist stakeholders to help develop scenarios, but effectively integrating stakeholder participation with scenario analyses and modeling remains a challenge. Using the New England Landscape Futures project as a case study, we explore how a method for codesigning a scenario elicitation process can be used to help balance the needs of both stakeholders and scientists. To illustrate the design process, we document eight influential decisions made with stakeholder input, describe the competing demands that we negotiated, and outline the rationale for the selected approach. We find that three priorities drove most of our decisions: maximizing stakeholder involvement in the scenario development process, efficient use of stakeholder time, and research needs. The outcome was a robust, intense, and highly structured one-day scenario development protocol that engaged stakeholders in the full scenario development process from initial orientation and identification of driving forces through to fleshedout scenarios narratives and quantitative inputs able to inform land-use simulations. Its deployment in six state-specific workshops was successful in eliciting divergent scenarios that stakeholders perceived as being plausible and relevant. Stakeholder responses to the process were positive, though also reflected the compromises made during the codesign process. Research needs were largely met, though initial expectations likely exceeded what could reasonably be elicited from a stakeholder group in one day. Our experiences highlight the importance of process design and how selection of scenario development techniques should follow from the project objectives, problem context, and stakeholder preferences for engagement activities. The use of a codesign framework that recognizes the challenges involved and engages stakeholders in the design process can act as a shared learning experience and contribute to greater effectiveness and impact for participatory social-ecological scenario processes.