The rocks we live among at the surface of Earth were once magma and at exceptional locations around the world we witness magma erupt to form new rocks. But where and how much magma hides beneath the surface today? This question is difficult to answer, even at a place like Yellowstone caldera that is famous for its steaming hydrothermal features and explosive volcanic origin. The seismic picture of what lies beneath Yellowstone has come into focus over decades as seismic field instruments, data analysis methods, and computing power have advanced. The presentation will highlight steps toward the modern understanding of why the Yellowstone volcanic field exists in the middle of a continent and where magma exists beneath the caldera today. It will also highlight how natural magmatic laboratories like Yellowstone can provide practical insights into the potential of geothermal energy systems and the ancient volcanic processes that concentrated minerals essential to the modern economy.