I have been at Olallie quite a bit this year (at least 8 times in July, I can't remember...). I have not seen any fish with parasites (yet).
Late in June, and early July I caught seven fish between 15 and 20 inches length, and sent back probably twenty that were about 10-12 inches. The larger fish all had orange toned flesh like salmon or steelhead (yum). I have been fishing from the bank near Peninsula campground using Powerbait of assorted colors about a foot off the bottom. I am surprised how many folks are camping at Peninsula especially on the weekends. Last Thursday night the campground was all but full. The weekdays are usually much more peaceful.
Since July 12 I have only hooked smaller fish and released all but a couple lunch or dinner fish. I wonder if most of the larger fish I caught earlier were from the "Trophy" planting that took place in late June, although I noticed that the largest one (19.5 in) had some damage to the tail, and suspect it was carryover from last year. It also seems like the fishing has slowed considerably as the temperature has gone up (no big surprise there). The water on the shoreline certainly seems warm late in the afternoons, and it has steam rising before sunsise. Last week three sunrises have yielded six fish of the smaller variety. All have been biting within about an hour plus/minus of sunrise or sunset, and I have had virtually no bites outside of that time frame. IMO there is no such thing as an afternoon bite on this lake (maybe for those guys trolling the cooler depths of the main water, but not for us shore guys).
I hiked into Lower Lake last Monday and threw my line in there with no bites (worms from bottom and also from the top with bobber), but again, it was no surprise being in the heat of the afternoon and all. Thinking about fishing some of the surrounding lakes for brookies and cutthroat at dawn or dusk as the summer progresses. Olallie lake is still as beautiful as ever, and always worth the drive in.
p.s. The blue Huckleberries are ripe down the hill at about 3600 feet...