Denver Public Schools' Professional Learning Center was still relatively new when it decided to tackle a problem of practice that has vexed systems and departments across the country: How to measure the impact of professional learning. To do so, the Professional Learning Center created a new comprehensive measurement approach--one that would design, test, and apply lessons learned from Learning Forward's Redesign PD Community of Practice and the work of Thomas Guskey. The complex task came with an added challenge: That program would be tested within the confines of another department's high profile efforts to launch an early literacy initiative involving 2,500 teachers. Ultimately, the initiative gave the center a strong foundation to continue measuring the impact of professional learning at the district and school level. Along the way were struggles, modifications, and lessons learned that eventually helped the program bear fruit.