The Wrangell Volcanic Field covers more than 400 square miles and extends from the international border to Glennallen, Alaska. The field is a continental volcanic arc which developed along a convergent plate margin above a Yakutat block related subduction zone. Heat generated within that subduction zone generated the volcanic magma source.
Quaternary surficial deposits are found within the park. The most extensive of these are glacial, lake and fluvial. Other Quaternary deposits include: beach and shallow marine sediments along the coast, eolian deposits, and mass wasting (rock glaciers, debris flows and slides and solifluction) features.
The area is seismically active because the Yakutat terrane is accreting to North America. The associated volcanism and active faults zones generate frequent earthquakes.