This study examines student reading engagement with children's science books in elementary classrooms. "Reading engagement" in science is conceived in terms of a Transmission-Transaction continuum. When centered on transmission, science reading entails passive reception of a textually encoded scientific message. By contrast, when science reading is transaction-centered, teachers and students actively engage in the negotiation of scientific meanings that transcend the text itself. Examination of reading engagement relied on a discourse-centered method whose analytical goal was to uncover and better understand meaning-making around textual artifacts. More specifically, it took the form of a discourse analysis across three science read-alouds. While meaning-making in one aloud reading was predominantly centered on transmission, the other two read-alouds were characterized by increasing levels of transaction. Further, adoption of transmissive or transactional strategies was consistent with how teachers perceived reading in the context of science instruction. This study underscores the multiplicity of ways that reading can be conceived by science teachers and approached in elementary classroom settings. It is suggested that a more sophisticated understanding of how to systematically engage young students with science texts can help elementary teachers effectively integrate reading with science instruction, meet literacy requirements of current science education policies, and recognize that science reading transcends passive reception of facts.