The creek flows southeast between Helena Ridge and the Sawback Range, and then south through a gorge known as Johnston Canyon.

The stream empties into the Bow River, south of Castle Mountain, between Banff and Lake Louise, at an elevation of 1,440 meters (4,720 ft).

As Johnston Creek approaches the Bow River, it flows through a large canyon formed by erosion over thousands of years.

In August 2018, a few of the "natural" trails near the falls were closed off, in an attempt to help recover the small nesting population of the American black swift.

A tourist lodge and large parking area is located at the foot of the canyon, close to the creek mouth, along the Bow Valley Parkway (Highway 1A).