Many thanks to Shawn for his helpful trip report and for sending me some photos of Hengst.
Here are Nathan's photos of our trip:
http://natedeb.com/krv/displayimage.php ... t=43&pos=0
After wrapping up the car against pesky marmots, we started out shortly before 9 am. We hiked through White Chief Canyon, visited the marble mine, found our way up to lovely White Chief Lake, then continued up the steep slabs to the ridge between White Chief Peak and Eagle Crest. Like Shawn, we found no register on the presumed White Chief Peak, but the views were great. Eagle Crest was a lot more fun with a bit of Class 3 climbing and some tricky (for us) route finding. There is a register on top, and also pieces of Karen's camera down in one of the cracks

I lost my camera off Sawtooth in MK almost exactly a year ago. If you go to Mineral King, wear a safety strap for the camera!!!
Hengst Peak was just across the high meadow, and we headed up about 4 pm. I was skeptical that we would make it in time, but my good friends convinced me to go on, and it turned out to be not nearly as hard as it looked. We did a little bit of unnecessary boulder scrambling on the way up, but found a good easy Class 2 route on the way down. Then we headed down the steep loose slope to Eagle Lake and returned to the trailhead just in time to not have to use our headlamps. The weather was perfect and the air was clear - a pretty near perfect day in Mineral King! (Well, if you must know, I tripped on a stupid rock coming down the trail and went sprawling, but no harm done.)
If anyone wants a hiking partner for Mineral King, be sure to keep me in mind, because I'm game almost any time!
Alice "Moondust" Hengst