You pick up the detour, wherever you want to. As I was hiking up out of Woods Creek, I kept an eye peeled for the best route/terrain to access Sixty Lakes Basin. I was lucky, I left the trail it looks like, just past Dollar Lake but before Arrowhead Lake, south bound. Looks like, just before getting to Arrowhead, there is a pass of sorts. If you look at your map, straight across from the top of Arrowhead is where you want to shoot. You have to contour around a little hill before you start up to that gap. I found parts of an old trail, so that was a good sign, indicating others used that route too. When you drop down the other side, you still have to drop some more to get into the basin, I stopped at a small lake for a rest before dropping down to the small creek that goes thru the basin. There are a few used campsites in the basin, you can tell not many people stay there though. I only saw two researchers netting fish out of one of the lakes, the morning I passed thru. It is a steep climb getting out of there, once you pick up the trail again. The map doesn't look it, but it was. I enjoyed my time at Rae Lakes and Dragon Lake more, but then I was fishing up a storm. Not that scenic back in there, but I did get a feeling of wilderness/isolation, so don't let me throw a curve your way. On the other hand, you would visit an area that is rarely seen. Sorry if my first post goes on, added info as I went.
Camping around Rae Lakes is done along the east side and the area between the two. The area between the two is pretty broken up, so you may get surprised by anyone/thing walking around. Bear boxes scattered here and there. Wish I was going, but I have bigger plans this summer.
The year I did the Rae Lakes Loop, a bear was hanging around the lower Paradise Campground, I never saw it, but it was in the area the first few hours I was there that I heard about. Mice did in some water bottles of a couple young guys I met at Lower Paradise the night they stayed at Upper Paradise CG. Those bear boxes are not necessarily rodent proof.
Piece of cake.