Having planned ascents of some peaks in Yoho National Park, three friends and I hiked in to a backcountry campground on the first day of our trip. After setting up our gear at the campground, we decided that we had time to ascend a minor remote summit before dinner, as it was still early in the day. We unloaded unnecessary gear our packs and after some easy bushwhacking headed up a moraine descending from the peak. Upon cresting the ridge, we determined where our objective lay and proceeded to traverse the ridge towards it. Below the summit block, we assessed our route options and determined that the ridge seemed simplest. There was some exposure on this route. After successfully navigating the ridge to the spacious summit, we took a few photos and then headed back. On the crux of the route during return, one of my friends fell, landing over 150 m below on a talus field. Since I was behind him at the time, I down-climbed the crux to reach our packs which we had left on a col for the final push to the summit. I then activated my Personal Locator Beacon (PLB) and descended to where my friend lay. I immediately began CPR. My other two friends soon arrived and assisted. Withing 15 minutes, a rescue helicopter was in the air and we signaled it. It was able to land about 45 minutes after the fall. Despite our best efforts and resuscitation equipment provided by the search and rescue crew, my friend could not be revived. The three of us assisted rescue personnel to load him onto a stretcher and carried him to the helicopter. We were all evacuated from the scene. Thanks to my PLB, we were able to get assistance rapidly. I never go anywhere in the outdoors without one. Search and rescue personnel also informed us that the PLB generates a stronger signal than similar devices, making it a good choice for terrain where signal reception may be an issue.