This is a difficult, but rewarding day hike. Start out from the parking lot and hike through the dense, cool forest. After a short while, you will emerge from the forest into a meadow. Cross a stream and continue through the meadow to an alpine area that is quite rocky. The trail is always apparent until you approach the bottom of the last climb to the fire lookout. You will need to go left here until you see the beautiful blue hues of Hidden Lake and scramble up the rocky backside. Watch your step! One could easily spend a full day on this hike. The views are breath-taking.
A good time to go is August or September after the snow is gone. Bugs can be annoying in the meadows and trekking poles are always help that the knees need. To get to the trailhead: Take highway 20 to Marblemount and when the road turns left, go straight over the bridge. This is Cascade River Road. You will see a sign for Hidden Lake Peaks. Turn and follow that road to the trailhead. If you go to far, you will end up at the trail head for Sahale Arm (which is another amazing hike!). The route is 3.7 miles one-way. Once you are out of the trees, you will be blasted by the sun so bring sun screen.