Built on the preexisting base of the Dana Center’s existing Urban Mathematics Leaders Network, the Aspen program integrated new school districts into the existing Math Network. Through skillful management of the agendas and relationships between the superintendents’ network and the mathematics network, the superintendents’ focus on secondary mathematics has increased the urgency and commitment felt by UMLN members and the superintendents’ have been presented with common challenges their mathematics leaders identified. For example, when mathematics leaders identified the design and use of district formative assessments as a significant barrier to effective implementation of their Algebra I programs, we developed a paper on this topic and focused a superintendents network meeting on helping them better understand the role formative and interim assessment can play. With input from both superintendents and their mathematics leaders, we have identified feasible targets for collective tool development and specific districts who are interested partners in developing and piloting the tools. The ULMN is led by Uri Treisman and his colleagues at the Dana Center/UT-Austin.