In this article, the authors describe how college transition programs and campuses can go about creating and curating a major and career ecology to support at-promise students and their major and career success. They review literature about the systemic barriers and lack of institutional support for at-promise students as it relates to their major and career development, describe the college transition and success program they studied, provide evidence about how it helped increase at-promise students' confidence in their major and career path, and then detail the role of offering a major and career ecology in developing at-promise students' confidence in their major and career trajectory. They end by comparing the major and career ecology approach to guided pathways--an intervention mostly implemented in community colleges intended to lay out structured paths toward degree completion--offering the major and career ecology approach identified in their study as a viable alternative for supporting at-promise students' success.