Notes

Death Valley's formation has to do with the movement of the earth's crust, or surface. The crust is made up of several plates, which shift over time. Long ago, this shifting brought magma, or melted rock, from inside the earth to the surface, forming volcanoes, and over time, the magma built up and the volcanoes grew into mountains. Later, the earth's plates split apart, forming the valley with mountains on either side.

The valley's geological features reveal clues about other events that occurred in its history. Over the years, the mountains have eroded, sending their debris to the valley floor. The climate of the area has also changed—during certain periods, the climate was more humid, allowing the snow from the surrounding mountaintops to form lakes in the valley. The water carved out shelves in the bordering rocks and mountains. When the climate became drier, the lakes evaporated, leaving sediment that built up on the rocks.