At 56 metres (180 ft) high, the American Falls is slightly higher than its Canadian counterpart.

Its crestline is 328 metres (1075 ft) wide.

The American Falls look spectacular at night, when it is lit with various combinations of coloured lights.

The natural bedrock is composed of soft shale and limestone. Over the years the continual flow of water causes large sections of bedrock to fall and remain at the base of the cataracts. Geologists predict that eventually the American Falls will transform into a succession of descending rapids.

The diversion of water above the falls has slowed the forces of erosion. It is estimated that 75,000 gallons of water flow over the American Falls each second, amounting to only 10% of Niagara's total waterflow.