Johnston Creek originates north of Castle Mountain in a glacial valley southwest of Badger Pass and south of Pulsatilla Pass, at an elevation of 2,500 metres (8,200 ft). The creek flows southeast between Helena Ridge and the Sawback Range, and then south through a gorge known as Johnston Canyon. As Johnston Creek approaches the Bow River, it flows through a large canyon formed by erosion over thousands of years. The creek has cut through the limestone rock to form sheer canyon walls, as well as waterfalls, tunnels, and pools. A popular hiking trail follows the canyon and leads to a meadow within the Johnston Valley above the canyon. The first part of the trail consists of a constructed walkway with safety rails and bridges, while the last part of the trail is natural and more rugged. Within the meadow are the Ink Pots, which are six blue-green spring-fed pools.