Much of the geographical features we take for granted, like lakes, valleys and mountains as well as our rich agricultural lands are thanks in part to glaciers retreating 20,000 years ago. Glaciers are thick, dense bodies of ice that cover large amounts of land, formed by unmelted, compacted snow over centuries. They move slowly, like an ice river, under the force of their own weight, forming drumlins, fjords and moraines. While almost all of earth’s glacial ice can be found in continental glaciers in arctic zones, glaciers can also be found in alpine and temperate regions in surprising places. Think of glaciers as giant water savings accounts: when fresh water falls as snow in cold, alpine areas, snow that doesn’t melt gets stored as ice. In warmer seasons, the glacial meltwater feeds rivers that flow downstream, providing freshwater for plants, animals and people. When there’s less than average snowfall or higher than average temperatures, glaciers retreat faster, with some predicted to disappear entirely. For locations like Alaska with tens of thousands of glaciers, glaciers are an important part of the environment, not only for tourism, but the meltwater from certain glaciers provides drinking water and hydroelectric power.