Trailhead: Park at the Chester Lake parking lot located on the east side of #40 gravel highway Smith Dorrien Spray Lakes road. 46kms south of Canmore across from the Burstall Pass parking lot. Note, Gravel road access only. Kananaskis Country.
Description: Locate the trail head on the far right side of the Chester Lake parking lot. If you decide to do the Headwall Chester Lake loop you’ll come out on the Chester Lake trail located on the left side of the parking lot. I’ve read a lot of conflicting trail descriptions leading to Headwall Lakes. This is a popular cross country ski area with several intersecting trails that can lead to a lot of head scratching.
Stay on a well worn double trail marked with orange ski signs for approximately 3kms until you reach the out flow from Headwall Lakes. Cross the creek walk up the hill another 100 meters or so keeping an eye out for a large cairn and well worn single trail located to your left. Continue on as the trail slowly ascends the valley towards Headwall Lakes.
Expect some flood damage along the outflow. Cross the talus slopes towards a treed headwall located in front of you then work your way up the trail as it steeply ascends the headwall below the lower lake. Once you arrive at the first lake you can continue on to the upper lake by passing the right east side of the lower lake and waterfall. Note that the top of the waterfall emerges from underground.
Views of both lakes and the valley below are stunning. From the upper lake strong hikers can complete the Headwall Lakes, Fortress Mountain and Chester Lake loop. The pass towards Chester Lake is the first one located on the left west side of the valley. Follow the valley another 1.5kms or so and ascend the scree and talus slopes towards the col located below Fortress Mountain. Once you arrive at the col you can hike another 472ms to the summit of Fortress Mountain or descend to Chester Lake.
Fortress Mountain is considered an easy scramble with one short cliff band below the summit. Expect 6-8 hours to do the 20km loop and Fortress Mountain. You can complete the loop in either direction however the preferred route is Headwall Lakes to Chester lake. The ascent to the Fortress Mountain col from Chester Lake is a long grind up loose steep scree which is much easier to descend. If you just want to summit Fortress Mountain, Chester Lake is a shorter route. You are in bear country