Approach
This is a 4900’+/- ascent day. The approach to Bourgeau is a long, but easy one. The Lake Bourgeau trail is 7.4 km. Don't rest at the lake, instead proceed on to the tarns above it another 2 km and take in the better views (one of these small lakes was still frozen in June). This is one of the best views of Mt Assiniboine, hands down.
Route Description
Once you take a large U turn at the tarns and gain the summit approach, Assiniboine is in clear view the whole way. I am sure a much shorter route could be negotiated from the Sunshine ski resort, but there is no official trail on the south side and travel in this sector has been prohibited in the past.
I did 2600' from the lake to the summit in 1 hour and 15 minutes. The ground is relatively free of scree and gently sloped. This is a busy mountain. I passed 5 climbers (each one from a different country) to be the first to the summit this day. It might be a good idea to set up a soda stand. The better mountain views outside of Assiniboine were Pilot and Ball. On return, I ran into a Hoary Marmot, which is a common sighting in the Canadian Rockies, even though they hibernate for most of the year. What was rare, was a pair of Pine Grosbeaks (overgrown red colored finch) at 6000'.
Essential Gear
Not much, just good hiking boots, poles, attitude and camera to take your best shots of Assiniboine.