Valley of Ten Thousand Smokes The ash-filled valley covers a area. The ash can be up to deep. In places deep canyons have been cut by the River Lethe, allowing observers to see the ash flow strata. Since the ash has cooled, most of the fumaroles are now extinct and despite its name the valley is no longer filled with 'smoke' (i.e. steam). Vegetation still does not grow in the valley. The signs of volcanic activity are still visible on nearby hills. Katmai's most recent eruption was in 1927, but there have been non-eruptive events as recent as 2003. The Alaska Volcano Observatory still monitors
Geology of the Death Valley area continental shelf was shortened and some parts of older formations were moved on top of younger rock units. The plutons in the park are Jurassic and Cretaceous aged and are located toward the park's western margin where they can be seen from unimproved roads. One of these relatively small granitic plutons was emplaced 67–87 Ma and spawned one of the more profitable precious metal deposits in the Death Valley area, giving rise to the town and mines of Skidoo. In the Death Valley area these solidified blobs of magma are located under much of the Owlshead Mountains and are found