The Hawaiian Volcano Observatory (HVO), now run by the USGS, studies and monitors volcanic activity. They have marked layers in this outcrop, including the 1790 footprints ash layer (at right), that can be traced around the park. Eminent volcanologist Dr. Don Swanson provides information on outcrops to visit.
All images copyright © 2016 F.W. Vollmer and may not be used without permission.