Grizzly bears are often seen in the summer. Encounters in the past have been mutually respectful.  It is good backcountry practice to hike in groups and carry bear spray, and know how to use it.

Summer at Assiniboine Lodge begins in late June with a celebration of the summer solstice. Signs of the quickly retreating winter are marked by buttercups and anemonies poking through the snow. The cheerful songs of the returning thrushes, the vibrant new growth of the larches and the leisurely stretching of daylight into the late evening bring magic to the landscape. The fishing is always good at Assiniboine, but early summer is a standout as the lake ice retreats. In early summer bring gaitors and be prepared to weave though snow patches in typical early season Rocky Mountain hiking conditions.

As the snowline moves to the peaks, the wildflowers explode into bloom in a sea of colour that blankets the alpine meadows. The flowers are usually at their peak between mid July and mid August, making this the most popular time to visit. Every colour of the palette is expressed in the Indian Paintbrush, forget-me-nots, asters and fleabane. Even mountain tops are dotted with the purple upward march of the moss campion. Paradise usually has two sides and the height of the flowers coincides with the mosquito and horseflies. 

The frost starts nipping in the middle of August and signs of fall gradually appear, turning the leaves crimson and yellow. Quiet returns to the alpine as the gophers make an early return to hibernation, the birds start heading south and the bugs face their demise with the frost. The larches take center stage in the middle of September. The light softens and the valleys become golden, the mountain peaks turn white and it is not unusual to have long stretches of brilliant weather until the beginning of October.