For several decades, science teachers have used bottles for classroom projects designed to teach students about biology. Bottle projects do not have to just focus on biology, however. These projects can also be used to engage students in Earth science topics. This article describes the Earth System Science Project, which was adapted and developed from the EcoColumn project and is geared toward middle and high school Earth science students. The project is an inexpensive model of a pond ecosystem, which demonstrates the interaction between the geosphere, hydrosphere, atmosphere, and biosphere. The project concludes with questions that incorporate several Earth science and biological concepts. Although this activity is reminiscent of other bottle biology projects, the Earth System Science Project was designed to fit specifically into an Earth science curriculum. (Contains 5 figures.)