Prior work suggests that recent graduates from teacher education programs feel better prepared to teach and are more instructionally effective when they learned to teach with more instructionally effective cooperating teachers. However, we do not know if these relationships are causal. Even if they are, we do not know if it is possible to recruit cooperating teachers who are, on average, significantly more effective than those currently serving. This paper describes an innovative strategy to use historical administrative on teachers to recommend the most instructionally effective and experienced teachers in various districts and subject areas to serve as cooperating teachers. In collaboration with a large teacher education program, partnering districts were randomized to receive either recommendation lists or use business-as-usual approaches. Those districts that received recommendations recruited significantly and meaningfully more effective and experienced cooperating teachers. Additionally, preservice student teachers who learned to teach in these same districts felt significantly better prepared to teach. This study offers an innovative and low-cost strategy for recruiting effective and experienced cooperating teachers and presents some of the first evidence that learning to teach with instructionally effective cooperating teachers has a causal impact on feelings of preparedness to teach.