I took the high route - from Necklace Valley, over Iron Cap peak, to the West Fork of the Foss river. Having failed to entice anyone to accompany me, I started walking a (to the tune of a very loud owl) a bit before 6AM, arriving at the end of the trail a bit after 9AM. The Necklace trail is in as good a shape as ever, and while requiring some care near one water/log/rockfall crossing it is mostly straightforward to follow. Walking at a steady clip kept the mosquitos away, though some campers that I met along the way complained of how bad they had been the previous evening.
In checking the Big Snow 7.5' map (the Green Trails map is inadequate for this route) there is an obvious way from the Necklace valley towards the eastern ridge of Iron Cap. I was surprised to find nearly a dozen campers at southern Tank Lake, though I'd seen no other sign of people since leaving Necklace. While I had preprogrammed my GPS with the route, this was unnecessary - the paper map and compass were more useful, though there are always differences between map and terrain. This is still somewhat slow going as the terrain has a great deal of talus, so I didn't get to the beginning of the challenging part until nearly 1PM.
The crux of this route is the route from about 5700' of elevation to the peak at 6347'. I had originally hoped to make my way to the crest of the ridge some distance from the peak, and follow the ridge to the top. Unfortunately the ridge is cut by deep slots too narrow for the map to show. Much of the this ridge is climbing (rather than scrambling) terrain. In retrospect I wasted at least an hour seeking a reasonably safe route up, and while I managed a gully fairly close to the top I feel sure there is a better way. It was also in this area that I had to cross some steep hard snow - this is not to be attempted without an ice ax. Mosquitos were slowing increasing in number and took advantage of my slower movements and inability to retaliate as my arms were generally occupied with my scrambling.
I finally crestied the top about 3:45PM. There was only one prior entry in the summit register for 2006. With wonderfully clear weather there were excellent views all around. I couldn't be sure, but it seemed from there that the western ridge would be passable - and it was. This makes for a much easier descent towards the West Fork. It still had some tricky places, so it took nearly to 5PM to reach point 6077. Once there you can see a wide array of the lakes that inspires so many when they see the Big Snow map (or Green Trails Skykomish).
From 6077 it ""looks"" like just a quick romp to Chetwoot. But no, its more talus hopping - easy but slow - so it wasn't until nearly 6:30PM that I finally found a nice big campsite between Chetwoot and Little Chetwoot. I was amazed to find two parties there. The bugs got less intense as darkness fell, so star gazing was quite nice.
Somewhat sluggish the next morning, I didn't start walking until about 8AM. There is a trail through the cliffy area adjacent to Little Chetwoot; then the trail to the south end of Big Heart lake is absolutely delightful, with great views, tons of wildflowers, and many picturesque tarns. I'd never seen hummingbirds drink the nectar of heather before! The route over the spine between Big Heart and Angeline can occasionally confuse, but there are many cairns. The day got pretty hot, especially that long descent northeast of Copper Lake.
Final trailhead time: 1:15PM.
The road between the WFFoss and Necklace trailheads is only about 2 miles, so even in the heat I was able to return to the car in 45 more minutes.
I have talked to a number of people who have expressed an interest in making this traverse, or something like it. The high route avoids most brush and many cliffy areas present at lower elevations, but still requires significant scrambling skills. Do not attempt this route unless you have (at a minimum) the scrambling skills equivalent to what you learn in the Mountaineer's scrambling course.