Better do this earlier in the season (see my previous trek). The snow on the ridge is practically all melted. So too much bushwhacking, and then boulder hopping without snow.
Instead of heading back on the ridge, I went down its southwest slope (its upper section still had snow) in boulders and snow, then trees, onto the trail to Rainbow and Island Lakes. However at the lake basin, it's all snow. Couldn't see any trail. I followed footprints to Rainbow Lake, but no prints to Island Lake. GPS map helps. Both lakes were melting.
I arrived at Talapus Lake TH around noon. Was lucky to grab a spot right by the parking spot. Many cars lined the bumpy road. Expect many hikers all the way to Olallie Lake. I didn't see a single soul once I cut off towards Pratt Mountain, and until I returned to Olallie Lake.
One lady who camped at Pratt Lake told me that there were bugs, but they were not really biting.
Order of the photos:
1) Talapus Lake
2) Olallie Lake
3) Pratt Mt view to the south (pano)
4) Pratt Mt view to the north (pano)
5) scramble talus to Rainbow and Island Lakes
6) Rainbow Lake
7) Island Lake