Mathematics success in high school is critically important for individual students and for the state. It provides skills and post-secondary opportunities that support a robust workforce. Designing and evaluating policies to improve ultimate mathematics outcomes requires first understanding the ways that students arrive at their destination. The sequential design of most mathematics courses shape how students can advance during school, leading to specific pathways through mathematics curricula. The shape of these pathways create critical moments of opportunity and lasting consequences. As the state shifts from a "one size fits all" model of high school curricula, it is important to isolate critical junctures students will face as they proceed through school. This brief maps students' progress through mathematics courses in the state, highlighting particularly consequential moments of transition. It asks: (1) Where are the key branching points as students progress through coursework in mathematics?; (2) At what branching points are social background disparities most pronounced?; and (3) How are divergent course branches related to the transition to post-secondary school?