I’m not a scientist or a geologist, so I’ll do my best to explain the caves in layman’s terms. The Sandy Glacier Caves on Oregon’s Mount Hood basically began with a small finger-sized tube of water, carving its way down and out the glacier. The water is a product of the melting glaciers, and the tube is a result of erosion. Over time, the tube has been weathered and crafted into a sort of shoot that gets larger and larger as it descends, spitting out into gaping holes. The bottom of the tubes eventually melt down to bedrock (the mountain), and there lie the wondrous caves. Water continues to flow through them. It’s wild. Pure Imagination, one of the Sandy Glacier Caves, has a raging river flowing through it. Another cave we explored is called Snow Dragon, but unfortunately, we visited in winter, so the water was buried under a base layer of snow. The craziest feature was the frozen waterfall near the entrance of Pure Imagination: a moulin (vertical shaft) formed from melting and erosion, just like the cave, and eventually, the water broke through and created the waterfall. When we were close to it, we could hear water still flowing through the middle, like it was hollowed out. I couldn’t have dreamt up something more mind-bending if I tried. At the end of the day though, these caves exist because Sandy Glacier is slowly receding into the shadow of Hood’s summit, and regrettably, someday it will cease to exist.