The US Forest Service was conducting the world’s largest climate change experiment near Marcell, Minnesota. The Spruce and Peatland Responses Under Changing Environments (SPRUCE) research facility is an experiment to assess the response of peatland ecosystems to increases in temperature and exposures to elevated atmospheric carbon dioxide concentrations. The MAPSS Summer Tour highlighted the work at SPRUCE on August 23, 2024 with pre-event points of interest the day before.