Thompson Lake via Mt. Defiance
ElevationAscent: 5,068' 1,545 m
Descent: -5,067' -1,544 m
High: 5,491' 1,674 m
Low: 2,209' 673 m
GradeAvg Grade: 12% (7°)
Max Grade: 52% (28°)
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“An airy trail with good mountain vistas, and ending at a nice lake pretty far out of the way.”— Dean Pospisil
The first stop will be Mason Lake where you can refill your water, stretch out, dip your feet. Continuing past on the marked main trail, you'll see signs where the trail splits to Mt. Defiance and Lake Thompson. Head that way. Again, there is a lot of fairly steep climbing. We were there at the end of May and there was a fair amount of snow to push through. Because of the snow, I would recommend at least having some boots, as kicking into the snow can be helpful for steeper portions.
Once you get to the turn off for Mt. Defiance (if it is a clear day) you'll be able to see Mt. Rainier to the south and maybe even Seattle to the west. You can drop your packs and head up for a better view (20-30 minutes one way), or continue to Lake Thompson. From here you'll cross over to the side of the ridge opposite I-90 and it will get much quieter with fewer people. Runners will first experience some descending before following the ridge for a while until popping up over a final ridge, where a steep switchback descent brings you to Thompson Lake.
In early May, this north facing ridge portion was fully covered in snow and difficult to navigate. To ease your travels, I would recommend poles, good footwear, and the Trail Run Project mobile app which helped us find our way!
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Land Manager: USFS - Mt. Baker-Snoqualmie National Forest Office