Far too many California students are falling off the pathway to and through college. At current rates of high school and college completion, only about 30 percent of California 9th graders will earn a bachelor's degree, a rate that is insufficient for an economy that increasingly demands more highly educated workers. In this study, the authors examine college pathways in high school, at California's community colleges, and at California State University (CSU). They find that most students exit the pathway in the last two years of high school or the first two years of college. In addition, they find that: (1) Most of California's high school graduates are not prepared for college. Even with significant increases over the past ten years, only 45 percent of the graduating class of 2016 complete the college preparatory courses--known as the a-g courses--required to be considered for admission to CSU or the University of California; (2) Even academically prepared students are falling off the pathway. Among our sample of high schools, students who successfully pass the first college preparatory math course, 34 percent do not take the next one--even though 13 percent earned an A and 22 percent a B in the class; (3) Eliminating progression problems in our sample of high schools would increase the a-g completion rate by 18 percentage points; (4) Students historically underrepresented in higher education are more likely to drop off the pathway at every stage; (5) CSU does not have adequate capacity to enroll qualified students.