Like much of the world, the United States is rapidly implementing the teaching of computer science into both primary and secondary school curricula. Uncovering what challenges U.S. schools in general—and rural U.S. schools in the unique environment of more mountainous regions of the U.S. in particular—face in implementing new curricula is not well established in the scholarly literature base. If reform advocates are able to anticipate implementation challenges, they might be more effective in facilitating needed changes. In response, the overarching research question is addressed: What are the challenges of delivering multi-age computer science in the rural, mountain regions of the western U.S.? This two-phase research project first identifies the anticipated challenges to implementing the curriculum by curriculum designers (Phase 1), and then goes on to compare those anticipated challenges to those identified by classroom teachers after completing a teacher training program (Phase 2). Thirteen teachers completed the training program in May and July of 2021, and five were selected to be interviewed. Transcripts of the interviews were analyzed in open, axial, and selective coding to identify recurrent and dominant themes. First, a qualitative methodology through the lens of the constructivist theory was used. Then, conventional narrative inquiry methods were employed to investigate the narratives using thematic analysis. The Phase 1 concerns of adhering to curriculum standards and using appropriate programming languages were contrasted to the Phase 2 themes of the future importance of coding for all students, confidence in pedagogy, the difficulty of coding, and issues of approval and safety. The results of this study serve as a bridge between the mandates created by education leaders and the actual experiences of the participating teachers tasked with delivering the curriculum.