It grinds, cracks and moans as massive pieces of ice split off and crash down. This is not your automatic icemaker on the blink. This is Glacier Bay doing what it's been doing for two centuries. The bay, once covered by sheets of glacial ice, is now a bay revealed. As the glaciers continue to recede, the bay enlarges. Back in 1879, naturalist John Muir was the first to note the glacial movement. Comparing charts from European explorers made 85 years earlier, he determined that the glacial ice had receded by more than 30 miles. Designated a National Park in 1910, today Glacier Bay is a 3.3 million-acre expanse that was buried under a mile-wide wall of ice only 200 years ago. Its natural environment includes five major land ecosystems including wet tundra, coastal western hemlock and spruce forest, alpine tundra, glaciers and icefields, and post-glacial meadows. Each week, dozens of ships traveling the Inside Passage spend the day cruising the 65-mile long bay. As each ship arrives, a National Park Service ranger boards the cruise vessel to provide a running commentary of the treeless mountains, icy fjords, hidden inlets and glacial landscapes as the ship passes by. Glacier Bay isn't just about ice. The ranger will also point out the killer and gray whales, sea otters, porpoises, moose, coyotes, wolves and bears visible in the sea or on the land. Leave your ice pick at home. But don't forget your binoculars.