Kenai Fjords was formed by Plate Tectonics. The Pacific Plate subducted beneath the North America Plate to form it. This process pulled the Kenai Mountains down into the Earth, along with some glacial features. The movement of the North Pacific Plate has created an assortment of terranes along the shoreline. 10,000 years ago, when a warming climate and snow that fell at lower elevations, and therefore melted sooner and stopped stopped making more glaciers, small islands formed around Kenai Fjords.
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