There has been a wealth of research examining learning environments as one of the variables that contributes to academic success for students studying science. A constructivist learning environment has been explored as one way to assist students in achieving greater success with science learning. There is a lack of research concerning how and if successful teachers continue to change over time. This study was designed to address such research gaps. The teacher leaders involved served as staff members for Iowa Chautauqua and continue to develop and improve in their use of constructivist practices. There has been a lack of evidence focusing specifically on how participation in the Iowa Chautauqua Professional Development Program actually increases use of constructivist teaching practices. Results of the research indicate that the teacher leaders continue to develop further in their use of constructivist practices over time. The Constructivist Learning Environment Survey (CLES) scores were used to indicate improvement. There are implications for planning and improving classroom learning environments for enrollees in new efforts that were suggested by teacher leaders.