Twenty years ago when the author was student teaching, he quickly learned what geometry teachers and researchers (e.g., Senk 1985) have long known: High school geometry students struggle with proof. Throughout his career, he has tried to create instructional materials to make proof more accessible to his students. From field-testing materials with his students and revising them, he has developed a proof progression that allows for differentiating instruction as well as ample time for students to develop their reasoning skills. Although he still has a few students who struggle with proof, those numbers have greatly decreased after using the progression.