Malignant Mushroom is a full 55 meters of waterfall grade 5 ice. It is important to note that Joe Josephson’s “Waterfall Ice: Climbs in the Canadian Rockies” guide book references that you can do this route with 50 meter ropes. We found that not to be the case. You will for sure need 60 meter ropes to do this route to the spot of the present anchor.
Malignant Mushroom is on the north side of Devil’s Gap. It is directly below the massive walls of Phantom Crag (aka Devil’s Fang) which sports some serious summer time rock climbing. It is the first waterfall ice you can see on the drive in, with Frozen Fungi and Sunshine visible further west on the same side of Devil’s Gap. The guide book instructs “Hike up through the trees to the right of the route. 30-40 minutes.” That is it. Neither my partner nor I had climbed Malignant Mushroom before and ended up ascending to the base of the Phantom Crag itself. We then traversed west and descended to the top of Malignant Mushroom. Therefore, we rapped the route before we climbed it. Our route was actually a joy as it followed a well trodden path to the base of some magnificent wall climbs on the Phantom Crag. But if efficiency is part of your game plan, you need to bypass the first trail you see on the right beyond the park boundary and continue down the dry creek bed/mud flats to a significant bend to the south (left). At this juncture, start your descent onto the slopes to your right, somewhat angling west until you hit a ravine filled with ice. Follow this up to the base of Malignant Mushroom.
If you are descending first, as we did, you will find runners placed along several different trees at the top of the route. If you work your way down to a tree closer to the top of Malignant Mushroom you can quickly lower yourself to a bolted anchor on the west side of the climb. Sometimes this anchor can of course be buried in ice.
There are several lines to choose from on ascent of Malignant Mushroom. There appears to be an easier route to the right via several ice steps. We chose pretty much dead center which better reflected a WI 5 climb. This was mostly vertical and well textured ice in March of 2006. Supposedly it has sported large mushroom features in the past; however, they are not an annual occurrence and did not exist during our climb.
If you did not do my recommended, but longer, approach, you can always descend the route from walking off the top instead of rappelling. Ascend the slopes to the east of the route until you run into the steep walls of the Phantom Crag. Then traverse right hugging the wall until you find a well traveled trail that leads back down via switchbacks to the boundary area.