Begin at the Slavonia Trailhead and start on the Gilpin Trail (class 1). At the wilderness sign-in, take a left to continue on the Gilpin Trail (right leads to Red Dirt Pass, another route). At the turn-off for the Mica Lake trail, continue straight on the trail heading to Gilpin Lake.
Continue on the Gilpin Trail until you reach a clearing at around 9700 feet. The trail will sharply turn to the right and cross Gilpin Creek. This is where you leave the trail.
This area receives little traffic away from the trail. Please follow Leave No Trace guidelines.
Instead of turning right with the trail and crossing the creek, turn left and follow a climber's trail through the willows heading northeast to a rocky cliff just east of point 10016. The prominent point to the east-northeast is Point 12006, and the summit of Zirkel is further north along the cliffs. Continue northeast to the base of Point 12006 at around 10400 feet. Follow a game trail up the west-facing grassy slope above timberline and to Point 12006. This slope is just south of Point 12006. This slope is steep, and you will gain elevation rapidly. Once at Point 12006, you still have ways to go.
Follow the ridge northeast to the well-defined plateau. This is the continental divide. Head north along the divide near the cliffs on the west side. The walking here is easy with the flat ground and flower-strewn short grass. The summit of Zirkel is near the northern-edge of this plateau.
Return the way you came, follow Red Dirt Pass back, or return via Gilpin Lake.
To return via Gilpin Lake, go back to Point 12006, and instead of immediately descending, descend along the ridge heading south. At some point you will want to bail off the ridge (it gets very rough) and head directly southwest to the beautiful Gilpin Lake.
None! Besides the ten essentials which you would be bringing anyway. In the early season an ice axe and crampons would be necessary for the ascent to Point 12006 (I have never seen enough snow on it for that during the summer).
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