Glacier caves of Mount Hood

On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing. In the past five years, we have seen the caves melt, shrink and collapse in a dramatic way. The caves are formed by water carving away at the ice.

Surface water makes its way downward through a fracture in the glacier and melts away a vertical shaft called a moulin. The water then travels down the moulin and downhill, thus creating a horizontal borehole passage. There are three explored caves in the glacier: Snow Dragon Cave, Pure Imagination and Frozen Minotaur. There is also one cave that has not yet been explored. — Josh Hydeman

Photography by Josh Hydeman

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