The primary source of water for the Great Basin's ecosystems is snowmelt from the mountains.

In the Great Basin, snowmelt from the mountain ranges is the main source of water for its ecosystems. During the winter, snow accumulates in the higher elevations, and as temperatures warm in the spring and summer, the snow melts and flows down to the valleys and basins. This meltwater nourishes rivers, lakes, and groundwater, supporting a variety of plant and animal species. Snowmelt is particularly crucial in the Great Basin, as the region’s dry climate limits other sources of water, making it vital for sustaining life throughout the basin.