College students with identities traditionally marginalized in scientific disciplines are more engaged and more likely to remain in science if they feel that they belong in their science, technology, engineering, and mathematics (STEM) classes and departments. In this qualitative case study, we elevated marginalized student voices to learn how departmental experiences shaped their sense of belonging in curricular and co-curricular spaces. Our research team interviewed 27 undergraduate life science students at a large predominantly white, research-intensive university. Participants reflected on their lived experiences and feelings of belonging within a biology department and shared their perceptions of departmental efforts related to diversity, equity, and inclusion. Three themes emerged as being of value to undergraduate students while they navigated the sciences: (1) implementing inclusive pedagogies, (2) providing co-curricular resources and support, and (3) humanizing life sciences education. These stories illuminated the importance of authenticity and intentionality in the implementation of strategies related to these three themes. This study provides an example of the power of centering marginalized students' lived experiences to identify strategies that can be employed more broadly to improve our courses, our departmental cultures, and our institutional policies--strategies essential to supporting students with a diversity of identities in engaging, belonging, and persisting in STEM.