Last night, after devising a hiking plan, I emailed John Kirk, who responded that coincidentally he was also planning to hike Whale Pk and the 2 12ers from Jefferson Lake the next morning.
From Jefferson Lake at 6am, we started bushwhacking up to Pt 12088. We left behind snowshoes and axes. We had little trouble with snow below treeline, and soon we reached dry open slopes. After an hour, we reached our first peak.
We continued towards Whale Peak, over Pt 12567 and a false summit. Contrary to my expectations, it was cold and windy. (Why I expected different from the Divide I don't know!) We reached our highpoint atop Whale Pk at 9am, seeing many familiar summits.
After a break we traversed along the Divide to Glacier Pk, then walked the long ridge down to Jefferson Lake. Along the ridge we encountered snow difficulties and decided to cut down to the lake sooner. The lake was thawing out, and we had a walk along the snow and rocks of the bank, completing our CCW loop at 11:30am. By now, it was very warm.
A short drive down the road led us to the Aspen CG area. We bushwhacked up to Jefferson Hill's north ridge. The summit area has a lot of scrambling. There are actually two summits, the northern with a spot elevation of 10511' and the southern with a 10520' contour. We agreed with the GPS that 10511 is actually higher. From the top, we took a more direct line down, reaching the truck at 1:10pm.
Our final summit was little more than a drive-up. Why bother? Well, by adding Michigan Hill, we would complete all five ranked summits on the Jefferson quad today. A road winds up Michigan Hill from the north; we parked as close to the summit as we could, happy to take a chip-in!