The National High School Center continues to receive inquiries about how to support high school implementation of response to intervention (RTI). Given the National High School Center's previous work on the topic, the authors wanted to better understand the conditions that contribute to or inhibit implementation of tiered frameworks in high schools and the role that district- and state-level leaders play in how these frameworks take shape in high schools. Although this brief uses some aspects of the authors' previous work as a way to frame this conversation, the purpose of this piece is not to create an in-depth portrait of how schools implement RTI but rather to discuss the state and district policies and activities that affect the implementation of RTI across the system--at the state, district, and high school levels. In order to explore these issues, in early 2011 the authors returned to Colorado's District 1892 to the schools they had visited in 2008 and interviewed district- and state-level leaders who could share their perspectives about implementation. In this brief, they summarize what they learned from these interviews and discuss the effect of district and state policies on RTI implementation in three high schools. In the process, they identify some implications for leaders at all three levels of the system as they address the sustainability of a complex framework like RTI. Although it would be easier to assume that the adoption of state policy is a sufficient mechanism for consistent and thorough implementation, in practice, they know that is rarely the case--local context and past practices all play a role in how initiatives such as this play out. Therefore, they also describe the role of local contexts and past practices within and across all three schools. In the first section, they summarize the previous work of the National High School Center, national policy efforts that have contributed to the emergence of tiered frameworks, and Colorado activities in response to federal policy and guidance. The second section describes four aspects that support RTI efforts at the state, district, and school levels: leadership, data-based decision making, interventions, and professional development. These four components have contributed to implementation at three high schools in District 189. In the process, they look not only at factors that support early implementation but also at those that advance and sustain implementation. They understand that much of the work by the Colorado Department of Education and District 189 toward sustainability continues to evolve and are grateful for their openness in discussing both successes and challenges. This story makes clear that although state-level policies can indeed support and accelerate implementation, district and school leaders' commitments to devote resources and stay the course play a pivotal role in sustaining implementation of tiered interventions at the secondary level. (Contains 1 table and 10 footnotes.)