We studied the outcome of a professional development opportunity that consisted of 2-week-long resident institutes for teams consisting of a secondary science teacher and two students. The science content of the National Science Foundation (NSF)-funded professional development institute was monarch butterfly ecology. The first institute took place in Minnesota during the summer, and the second in Texas during the fall. Staff scientists provided intense instruction in inquiry, with numerous opportunities for participants to conduct short inquiry-based research projects. Careful attention was paid to introducing each step of the full inquiry process, from asking questions to presenting research findings. All participants conducted independent team full inquiry projects between the two institutes. Project findings show that the number of teachers providing opportunities for their students to conduct full inquiry increased significantly after their participation. A mixed-methodology analysis that included qualitative and quantitative data from numerous sources, and case studies of 20 teachers, revealed that the characteristics of the program that helped teachers successfully translate inquiry to their classrooms were: deep science content and process knowledge with numerous opportunities for practice; the requirement that teachers demonstrate competence in a tangible and assessable way; and providers with high expectations for learning and the capability to facilitate multifaceted inquiry experiences. © 2005 Wiley Periodicals, Inc.