In this article, the authors describe an investigative activity in which their eighth-grade students reconstructed past environmental change in the New England area using data from lake varves in central Vermont to examine evidence of climate change. The investigation uses an authentic paleoclimate record (Ridge 2011) from the Pleistocene epoch, circa 15,000 years ago, a time following the last glacial maximum. When they initially assessed their students' climate change knowledge, the authors found that their students had relatively little understanding of paleoclimate proxies. After completing this activity, students' understandings of climate proxies significantly increased. This investigative activity is aligned to the National Science Education Standards on Earth's history and the crosscutting concepts of patterns, stability, and change discussed in the 2011 "A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas" (NRC 2011), and illustrates how sediment layers provide important evidence of how climate conditions have changed over time. (Contains 5 figures.)