A fragile snowflake descends from the sky and gently joins the living force of a glacier; a power strong enough to carve valleys and sculpt mountains.

My first experience with Alaska’s glaciers was a flight over blue ice in a Cessna 180. It is hard to imagine the intense pressure created by tons of ice, snow and sediment as it imposes itself on the landscape. With cracks along its skin, the glacier’s crevasses are deep enough to swallow 20-story buildings. Hushed by awe, the passengers in our plane were quiet as we absorbed the scene below. We felt minuscule, like a whisper in a windstorm.

Later, when our sons were in grade school, the boys and I cross-country skied to the base of Byron Glacier in Portage Valley. Behind a tiny opening of snow at the mouth of the glacier lay an expansive ice cave, as spacious as a gymnasium. Unaware of the potential hazards, we explored with sheer wonder, a castle made of ice.

Glaciers are rivers of ice responding to gravity, temperature and the geological features of the land on which it flows. Glaciers hold 77 percent of the world’s fresh water, and cover thousands of square miles in Alaska. The speed of an advancing glacier ranges from a few centimeters to more than ten meters per day. Periodic surges can result in advances of hundreds of meters per day. Most of the world’s glaciers are retreating, however, a phenomenon that many scientists attribute to global warming.

Tidewater glaciers calving into the ocean leave spectators breathless with their crashing drama. The icebergs formed by this process move and change with a life all their own. The tides, the wind, the sun and rain all chisel at the surface, creating a continuous art-in-progress.

Four years ago, I spent several days training on the Matanuska Glacier for an upcoming climb on Mt. McKinley. The course taught safe glacier travel and crevasse rescue. As part of our learning, we each had the opportunity to rappel inside a glacial crevasse. When it was my turn, I descended into a world of blue ice where I hung from a harness while my classmates above attempted to “rescue” me from a simulated fall. The eerie silence was broken only by the trickle of water and the moan of moving walls of ice. I reached out to touch the ice wall and it seemed as though I was touching the flank of a living creature, ancient and mysterious.

Like the face of the glacier itself, I rarely come away from these giants unchanged. Encounters with moving rivers of ice give me a sense of perspective about my place in the universe. And a rich, abiding awareness of the creative Force that moves mountains and spirit alike.