I had a venture into the Northwest Cascades that included a chance to check a couple of old quarries. The quarries were readily apparent in lidar bare earth imagery, but a bit obscured on the ground as the forest had grown up around them. The first quarry mine floor was being pioneered by a mix of cottonwood and red alder trees.
The geology of this area east of the South Fork Nooksack River is mapped as Darrington Phyllite and glacial drift and the quarries were in both formations with the one pictured above being in the Darrington Phyllite. The quarry exposed the highly deformed phyllite that includes a range of tight folds, kink bands and mini slip zones.