It was one of the underground volcanic extrusions investigated by the 2004 Gulf of Alaska Seamount Expedition.

To achieve this we created a full-coverage swath bathymetry map of each seamount and its surroundings, and we collected rock samples at all possible depths."

-Randy Keller, Oregon State University[3]On August 6, 2004, the DSV Alvin dropped down near the Denson Seamount and collected basaltic rock to try to determine the age of the seamount.

The search was difficult because the salty water had altered the volcanic rock over time, but they determined in lab tests that the Denson Seamount was about 18 million years old.

The team used bathymetric mapping to render three-dimensional images of the Denson Seamount and its counterparts.