The caravan took a tour of the Columbia Glacier on Prince William Sound. The glacier started receding in 1984 and has retreated 13 miles in the 31 years since. We saw it calf an ice berg the size of a bus. The water was full of ice floes and ice bergs. Sounds ranged from popping ice in the water to the sound of thunderclaps from the glacier. It was very exciting. Note the sea lions lounging on the ice.