The "Collaborative Research Project" ("CRP")--a mathematics research experience for undergraduates--offers a large-scale collaborative experience in research for undergraduate students. CRP seeks to widen the audience of students who participate in undergraduate research in mathematics. In 2015, the inaugural CRP had 100 undergraduate participants from across the United States; they collaborated on a month-long research effort applying tropical geometry to phylogenetics. CRP is envisioned as an annual event, one that scales to accommodate large numbers of interested students. This article describes the motivation for CRP, its structure, and the results of its inaugural iteration, and closes by assessing its future.