We’d been wandering underground for hours. Around 10 p.m., my wife Jess and I stood up in a circular chamber maybe 50 feet across. A waterfall at one end blew an icy mist. I flicked my lighter to see which way the air was moving—in this cave, the wind blows from entrance to exit. The flame was dead still.
We thought we’d done this the right way. Every year, we pick an adventure to celebrate my birthday, and for this one, we selected the Darby Ice and Wind Caves, tucked into the western slope of the Tetons.