Holding the Falls Together

Niagara Falls is always changing. The same forces that created it are still at work.

Water seeps into cracks. Winter freezes widen those cracks. The softer rock beneath the hard surface slowly wears away. Over time, sections of cliff can collapse without warning.

In 1954, a major rockfall changed the look of the American Falls. Huge boulders from that collapse are still piled at its base today.

To prevent sudden collapses near viewing areas, roads and buildings, engineers quietly reinforce parts of the cliff. They drill long steel bolts deep into unstable rock, add drains to relieve pressure from trapped water, and watch for movement with survey equipment and sensors. Engineers even turned off the American Falls in 1969 to study it — see sign 10, When the Water Stopped.

The goal isn't to freeze Niagara in time. It's to slow down dangerous collapses while letting natural erosion continue. The Falls may look eternal — but they are constantly being watched and carefully maintained.