The extreme floods of 2022 in Yellowstone showed much of their greatest power and effects in northeastern Yellowstone, the location of this field course. Such a rare event raises a number of intriguing questions: Have floods of this extraordinary magnitude occurred in the recent past, or are they unprecedented, as some have suggested? What is the evidence for large floods in the recent geological past, and how do their impacts on floodplains and riparian vegetation compare to those of 2022? There are several basic processes that have produced historic floods in northeastern Yellowstone, of both natural and human origin – how do these differ in their nature and effects on the ecosystem? Have floods played a significant role in landscape change over the millennia since glaciers last retreated from Yellowstone? We will examine the field evidence at key localities along the spectacular mountain valleys off Soda Butte Creek and the Lamar to address these questions. We’ll also measure discharge in a gentle stream to understand how flow is quantified and to compare with the impressive peak discharges in 2022 and earlier floods. We will also consider the meteorological and longer-term climatic conditions associated with flooding and how ongoing climate change can be expected to alter Yellowstone’s flood activity.

About the instructor

Grant Meyer is a geologist specializing in geomorphology, the study of processes that shape the Earth’s surface, including the action of water in both liquid and solid forms, as well as biological processes. Grant has reveled in exploring Yellowstone’s unique landscapes since he first set foot in the park as youngster in the 1960s. He is a graduate of the University of Idaho (BS), Montana State University (MS), and the University of New Mexico (PhD). Since 1983, he has investigated a variety of research topics in Yellowstone, including long-term deformation in the caldera, the effect of forest fires on erosion and sedimentation, climatic controls on fires, the long-term effects of beaver activity on streams, and the history and impacts of major floods, the focus of this course.