A Quaternary? landslide damed Sourdough Creek in the Gallatin Range, Gallatin County Montana and formed a
lake near Bozeman Montana. This landslide was used as the foundation for a dam which created a reservoir.  
The dam has since been breached by engineers because of safety concerns.  The landslide not only created Mystic Lake,
but also small ponds in the rumpled topography of the landslide.  These small lakes can be seen south and east of the
red word Gallatin.  

Can you draw a boundary or contact around the landslide based on the disrupted topography?

This image was captured from TopoFinder II on the Montana Natural Resources Information System
from an area between Mount Ellis and Hyalite Peak in Gallatin County, Montana.  For additional information
contact Steve Custer, Earth Sciences, Montana State University, Bozeman, MT 59717-3480
scuster@montana.edu