Sounded like an interesting hike so we headed out along Highway 1A (Bow Valley Trail) from Canmore for about 10 minutes before arriving at the Grotto Pond Day Use Area.
The first section was frankly not too interesting with a minor climb along a very rocky trail. There was an industrial plant off to the left humming along. After about 20 minutes we came to an open area with a bench overlooking a former gravel pit, Gap Lake and the scenic Bow Valley to the west towards Canmore framed by mountains on both sides. Overall you can expect a 50 meter (150 feet) elevation gain.
You now enter the Grotto Canyon walking up the creek bed as it twisting. There was not a lot of water flowing during our late May visit which made it easy to cross as we had to follow the best route up this narrow canyon. In sections the grips of winter remained as we had to walk across the tops of the ice although mud had been frozen into the surface providing traction.
In one section the canyon widened a bit and we discovered several sets of climbers tackling the canyon walls. We also meet a school group; guided tour and many other individual hikers during our visit to this popular trail.
On the left of one canyon wall pictographs could be barely seen (viewed best through camera lenses) and we could make out a canoe, person and a few other items. Further up on an elbow turn water falls could be seen. Just past this section the trail opens up a bit.
The guide mentions that Grotto Canyon changes with the seasons as the canyon floor is likely to be wet with a light-flowing creek. In early spring snowmelt can cause the creek to flood. And apparently in winter it is magical when the canyon floor freezes into a sheer sheet of blue ice (we still saw the remains of this in late May) and ice cleats are recommended.
If in the Canmore area the 4 km (2.5 mile) Grotto Canyon makes for an interesting light/moderate level hike.