Mount Decoeli is a pyramidal peak you can see from Haines Junction. From the summit on a clear day you get a sweeping view of the mountains, valleys, and icefields of Kluane National Park.
From Haines Junction, drive north along the Alaska Highway for about 20 kms. Just north of the Bear Creak Summit sign, there is a pull-out on the left.
Start by walking to the south-end of the pull-out. Continue walking in the grass towards the trees, and you should come across an obvious wide path through the forest. Follow the path until you reach the creek bed.
At the creek bed, turn slightly right, and head up along it. Continue following the creek. You may have to dodge into the bushes every once in a while, and you may want to cross the creek here and there. Your actual route will depend on the height of the creek, but overall the going is fairly straight-forward.
After about 5 km you will reach the base of a rock glacier. To your right is a worn trail that leaves the creek bed and starts climbing up onto the grassy slopes. Follow it upwards.
Hiking on the grassy slopes is a relief from hiking on the creek bed, but you will now start to climb upwards. Above you is the summit of Decoeli. You will be heading slightly to the left of the peak. Angle towards the high grassy slope on the left of the peak.
You will soon leave the pleasant vegetated slopes and eventually reach the talus slopes that lead to the summit. Hike up the talus slope to the shoulder below the summit (again, heading slightly to your left). Then look up and hike the final talus slope to the summit. This part is not particularly fun, as the rocks are loose and for every two steps you take up, you will slip one step back.
Eventually your hard work will pay off and you will reach the summit. The views are incredible in every direction. You can see deep into the St. Elias icefields as well.
There isn't much snow in this wind-swept region, so winter doesn't provide too many challenges. The creek is frozen and packed snow can make the going fairly easy. You are however still in avalanche terrain once you reach the base of the mountain and moraine.
From the south end of the pull-out, there is an obvious trail. You will follow along this trail which is along-side the creek for about 5 km. At about KM 5, you will reach the base of a rock glacier.
The rock glacier is a decent place to camp if you are staying overnight. It is at the base of the mountain and right before any steep inclines.
From the moraine, walk up the far scree ridge to the right side of the valley. Follow the ridge all the way to the summit. It is basically scree the whole way up for the most direct route. If you head further up the valley there is a less direct route with less scree. Return the same way.