 mount katmai is a large stratovolcano (composite volcano) on the alaska peninsula in southern alaska, located within katmai national park and preserve. it is about  in diameter with a central lake-filled caldera about 3 by 2&nbsp;mi (4.5 by 3&nbsp;km) in area, formed during the novarupta eruption of 1912. the caldera rim reaches a maximum elevation of . in 1975 the surface of the crater lake was at an elevation of about , and the estimated elevation of the caldera floor is about . the mountain is located in kodiak island borough, very close to its border with lake and peninsula borough. ==geology== mount katmai is one of five vents encircling the novarupta volcano, source of the vei 6 eruption and associated voluminous pyroclastic flows in 1912. the volcano has caused ten known fatalities due to gas exposure. katmai consists chiefly of lava flows, pyroclastic rocks, and non-welded to agglutinated air fall. the quaternary volcanic rocks at katmai and adjacent cones are less than  thick. much of the volcano is mantled by snow and ice and several valley glaciers radiate out from the flanks. katmai volcano is built on the sedimentary rocks of the naknek formation of late jurassic age, which are exposed just west of the caldera rim at an elevation of about , as well as north and southeast of the crater. sedimentary rocks have been reported at an elevation of over  in the west wall of the caldera and near the bottom of the eastern wall near . 300px|thumb|right|map showing volcanoes of alaska peninsula. ==volcanic activity== little is known about the historical activity of katmai volcano before the great 1912 eruption. early u.s. coast and geodetic survey maps suggest a pre-caldera summit elev
Active_volcanoes Aleutian_Range Crater_lakes Katmai_National_Park_and_Preserve Landforms_of_Kodiak_Island_Borough,_Alaska Mountains_of_Alaska Stratovolcanoes Volcanic_calderas_of_Alaska Volcanoes_of_Alaska