No-one knew how deep the highest large lake in the Sierra was, so we carried a packraft over Shepherd Pass and found out: 117 m. 93 km walked, 6 days, and 4.7 km paddled at 12,900 ft. Wikipedia claimed not to know. We commissioned satellite imagery to confirm it was ice-free, hauled an ultralight packraft and sonar sounder up the brutal Shepherd Pass trail, and sounded the basin. USGS topography predicted 25–40 meters. The actual sounding: 117 meters (384 feet), making it the 25th deepest natural lake in North America, and by far the deepest lake on Earth for its surface area. caseyhandmer.com