This article presents the findings of an evaluation of the eMINTS (enhancing Missouri's Instructional Networked Teaching Strategies) professional development program. eMINTS is an intensive teacher professional development program designed to promote inquiry-based learning, support high-quality lesson design, build community among students and teachers, and create technology-rich learning environments. This evaluation included 60 high-poverty rural schools across Missouri that were randomly assigned to two treatment conditions and a control condition, with approximately 200 teachers and 3,000 students in the 2011-2012 baseline academic year. The researchers conclude that after 3 years, the eMINTS treatment group and an eMINTS treatment group with an additional year of Intel support resulted in changed teacher instructional behaviors and increased student achievement in mathematics.