College students in natural resources continue to encounter instructor-centered teaching, despite strong evidence that suggests active-learning experiences benefit students more than passive learning activities. Case studies provide an active-learning alternative to lectures by teaching students new content and challenging them to engage in contemporary and relevant natural resource issues. In this article we present an interrupted teaching case that introduces students to problems associated with invasive species and the challenges of ecosystem-level management. We challenge students to assume the role of a lake manager that is faced with the introduction of a non-native plant about which little is known. Invasive species are a key area of research and management in the fields of ecology and natural resources. Students hoping to pursue a career in these fields should possess critical analysis, creative thinking, and collaboration skills, which are all fostered through the uses of case studies in the classroom. The interrupted case study technique used here models a real-life management experience by asking students to think critically about scientific information that they are provided, develop a study to collect information, make management decisions based on a suite of information provided, and finally to justify their management decision in light of prior and current knowledge. This case study is based on a wide-spread invasive species problem; one that has yet to be completely solved, although there are several success stories.