This article presents the design of an immersive simulation and inquiry activity for technology-enhanced classrooms. Using a co-design method, researchers worked with a high school biology teacher to create a rainforest simulation, distributed across several large displays in the room to immerse students in the environment. The authors created and evaluated two iterations of a design where students gathered evidence of evolution using networked tablet computers that scaffolded their interactions with peers and with the room itself. Outcomes suggest that the immersive simulation engaged students, helped them to establish and build upon ideas about evolution and promoted learning of challenging biological concepts. Student explanations from the second implementation demonstrated increased variation in ideas about evolutionary topics compared to those in the first iteration. Relevant design features from the two iterations are discussed.