The implementation of "research-based" mathematics curricula is increasingly becoming a central element of mathematics education reform policies. Given the recent focus on grounding mathematics curriculum policies in research, it is important to understand precisely what it means for a curriculum to be research-based. Using the Curriculum Research Framework (CRF), this paper examines the development process of Math Trailblazers to help situate decision-making processes related to curricula in the broader mathematics education policy landscape. In the process of developing and revising the curriculum, the development and research teams have specifically developed field test materials, researched ways in which teachers and students use and learn with the materials in a small number of classrooms, and then completed research-based revisions of the curriculum materials. While certain elements of the CRF are represented in the research and revision process, other elements, such as why and under what conditions the curriculum is effective, are underrepresented. Making visible research and development processes of research-based mathematics curricula has profound implications for understanding the effectiveness of certain policy initiatives. Merging policy, practice, and research is a difficult activity, but a critical one for enhancing the effectiveness of these fields in education. As these fields become increasingly intertwined, policymakers should be sensitive to the different demands of each field, and look for opportunities to enhance the capacities of organizations that exist at this nexus. (Contains 8 notes and 1 figure.)