The Rainbow Lake Trail is one of the most accessible and iconic hikes in the Whistler area. From a small parking area on Alta Lake Road just west of Whistler Village the trail immediately begins climbing through dense forest alongside 21 Mile Creek, a preview of the long steady climb ahead that eventually ascends 830 meters over 8 kilometers (900 meters if you continue on to Hanging Lake/Madeley Lake).
The trail is wide, well groomed and well maintained, and it is easy to follow as it weaves through diverse forests and subalpine meadows, following 21 Mile Creek up to its headwaters at Rainbow Lake. Here, the crystal clear water and idyllic scenery make it difficult to resist going for a dip, but swimming as well as camping, fishing, campfires, motorized recreation, and dogs are not permitted in the 21 Mile Creek watershed in order to protect Whistler’s drinking water. Note that all of these activities are permitted just over the ridge at Hanging Lake and on Mount Sproatt.
Most day hikers ascend from the Alta Lake Road Trailhead and then return the same way. However, if you have organized a ride back to town, the Rainbow-Madeley Trail is another good option that’s a little more challenging and interesting than heading back down to the original trailhead. Continuing on over the ridge directly west of Rainbow Lake is Hanging Lake, which has a small campsite with a pit toilet.
From here the trail becomes much rougher and more challenging as it descends and traverses steeply into the Callaghan Valley, through some very rugged terrain, across scree-fields, and through stands of massive cedar and Douglas fir. Eventually it emerges at a trailhead with a small parking area on a gravel road that is accessible for most cars. A junction with the Madeley Lake Loop leads around the east side of the lake to the campsites just prior to reaching the gravel road and near the end of the road at the north end of the lake. This is an absolute gem of a spot with free camping, sandy beaches, and great fishing. Consider putting some supplies in your shuttle vehicle, as it may be tempting to stick around for a while.