Approach
This is a 6300’+/- ascent day. You must register to climb Mount Stephen at the Field Yoho National Park information center due to the fossil beds you will cross on the trail. They open at 9:00 AM (2005). Park at the Mount Stephen trail head in the town of Field at the end of 1st Street (southeast corner of town). Ascend the trail for several thousand feet beyond the fossil beds (tons of fossils).
Route Description
The trail will peter out as you ascend steeper and rockier terrain. You will eventually come across some easy red rock bands. Just continue to ascend northeasterly until you top out onto a wide shoulder of Mount Stephen at 8000’. There is a built up bivy at this spot. Then turn due north (left) towards the mountain and ascend 400' up a gully through another rock band. Travel another 1400' of large scree to the base of the summit block. The last 700'+/- is the crux.
There are several cairns and markings, but I just soloed what I could find straight up the mountain, mostly about three to four 20 meter sections of solid rock (by Rocky Mountain standards) in the mid 5th class range. I topped out onto the summit ridge and had to traverse over to the summit which includes a weather station equipped with water, safety equipment, etc. There is an exposed notch on the way over that you need to jump over to a short rock face climb with a 5th class move or two. This step is not so difficult, but offers an airy feeling making the transition.
Return the same, however, you will find safer down climbing options with the broader view offered on descent.
Essential Gear
Helmet, alpine ax, bear spray, map, compass, some mini crampons and plenty of water, mostly a dry route.