Glacial concentrations surround all major peaks. Mt. Baker's slopes support 13 glaciers. Glaciers are sensitive to changes in temperature and snowfall. Their constant changes are important climatic indicators. They influence vegetation patterns, move and carve rock, add minerals to the ecosystem, and serve as reservoirs for domestic and hydroelectric water supplies.
Glaciers have tremendous effects on the hydrology of streams.
The most important effects are related to changes in the supply of runoff from melting and the seasonal storage of water within glaciers. In drought years glacial meltwater is the only thing flowing in some streams. Salmon exist in some streams of the North Cascades because of glacial meltwater. Streams that begin as glaciers have water that is typically cloudy and cold. When sunlight hits the surface of the lake, it is refracted at a different angle because of the fine rock flourlike particles.