Out of school time (OST) STEM opportunities are often presented as ways to support student achievement, understanding, and identity in STEM. Recent work has begun to explore how OST programs function within the STEM Learning Ecosystem, a holistic view of the various STEM learning opportunities available to youth in a given area. In order to increase understanding of how microcontexts impact the STEM Learning Ecosystem, this study explores the experiences and perspectives of three groups of participants in a network of after school STEM Clubs: youth participants, college student facilitators, and sponsor teachers. Based on interviews with all three groups, results of comparative case study analysis revealed two cases: Narrowed STEM and Expanded STEM. Youth in the Narrowed STEM case had traditional perspectives of STEM as hard, for smart people, and related to behavior; made only weak or no connections between STEM in different contexts; and had tentative STEM identities. Youth in the expanded STEM case had more active perspectives of STEM as exploration and problem solving, saw clear connections across contexts, and had decisive STEM identities. Critical Discourse Analysis was used to show how facilitators and club sponsors negotiated macro-level discourses of STEM and urban education in ways that aligned with youth views and influenced interpretations of the STEM Club. We highlight a need for critical and multiscalar evaluation of STEM Learning Ecosystems, particularly in urban areas, so that learning opportunities are available to all students, particularly those from groups historically excluded from science and STEM.