A solid frost overnight and gorgeous weather convinced Doug Sturm and I to head out one last time this spring to explore Mendenhall Glacier’s underworld. The ice conditions near the terminus were unpredictable, and neither one of us had any desire to head back into the huge caverns there. New pressure ridges were a clear indication of recent calving events, and we stayed away from this unstable area. Climbing up along the lateral moraine we noticed how much melt had occurred in the past few days. A small ice cave we had explored a couple of weeks ago had collapsed, and water was running everywhere above and under the glacier. Equipped with crampons and ice axes, we were able to push much deeper into one of the giant caves, despite water running everywhere. It was humbling to be standing in the belly of the glacier, witnessing up close how the massive weight of the glacier had ground even the most solid rocks into dust. Needless to say that he different hues of blue were an incredible feast for the eyes. As we headed back to the lake, we knew we would never again see the caves like we saw them, as soon they will collapse or melt away. We agreed how fortunate we are to be able to experience this ephemeral world of ice right in our front yard.