The Eagle County Math Science Partnership Integration Project (MSP-IP) is a multi-district partnership involving 17 schools in six Colorado school districts: Eagle County, Archuleta, Centennial, Ignacio, Montezuma-Cortez, and Silverton. The project is focused on developing the capacity of Teacher Leaders to implement the new Colorado Academic Standards in Mathematics (CAS-M) in ways that support intended student learning outcomes. Student achievement in all schools participating in this project was lower than the state averages and without a system designed to increase teacher capacity, student achievement would likely decrease. Through the project, 17 Teacher Leaders representing 17 different schools received intensive professional development to equip them to understand the content and practices in the new mathematics standards; develop expertise in analyzing student data; and become learning facilitators for the other mathematics teachers in their schools. RMC Research is evaluating the MSP-IP project activities by the use of multiple methods including interviews, focus groups, observations of classroom instruction and professional development sessions, and analyses of teacher and student data. So far, evaluation findings indicate some evidence of increases in the quality of math instruction in participating schools and some positive differences in achievement scores at certain grade levels when results are contrasted with a similar group of comparison students.