The Increasing Course Rigor Pilot Project, a joint initiative of the National Governors Association (NGA) Center for Best Practices and ACT, Inc., is one component of Phase Two of the NGA Center for Best Practices Honor States Grant Program. The project, which began in winter 2006 and concluded in summer 2007, was designed to improve the quality of learning experiences in core preparatory high school courses. The project was also a natural extension of ACT's efforts to improve the quality and consistency of high school coursework. In particular, it is a response to empirical evidence demonstrated in the 2004 study "On Course for Success: A Close Look at Selected High School Courses That Prepare All Students for College" (ACT and The Education Trust) indicating the need for increased rigor and relevance in core preparatory courses. This report describes the results of the 17-month pilot. Both qualitative and quantitative findings are presented, along with implications for policy and practice. The report concludes with a discussion of lessons learned and recommendations for next steps. Appended are: (1) State Team Members; (2) Student Population Characteristics; (3) Teacher Participation Details; (4) Project Activity Time Line; (5) ACT's Data-Feedback Model; (6) Distance Conferences and On-Site Collaboration Meetings; (7) Project Web Resources; (8) Number of Teachers Responding to Surveys; (9) CARS Alignment Results; (10) ACT Instructional Units; (11) End-of-Course Assessment Mean Scores; and (12) Rankings Based on Participation Levels and Testing Data. (Contains 12 tables and 4 charts.)