Drought over the past 20 years in the Colorado River Basin, and a growing demand for water, have brought Lake Mead to historically low levels.

In 1972, the year Landsat 1 captured its first images, Lake Mead’s elevation was 1,155 above sea level.

50 years later, Landsat 9 shows its water level at 1,041, as low as it’s been since Hoover Dam was completed in the 1930s.

The lake level reduction is even more extreme than shown by Landsat because of the steep topography.