Lots of water still in late July and tough to cross the creek. Recommend moss soled boots and the buddy system at all time for safety. Waders were not necessary as the water is plentiful but not that cold if you compare it to the beaches of Northern California at least. I think waders are dangerous too. They can fill with water.
I did some detecting. Allot of hot rocks near the creek that were not tuned out with my pulse induction detector! Recommend finding some areas close to bedrock for better detecting. Good luck finding those! Bring a GPS to be sure you stay on the GPAA claim. There are adjacent claims!
Crevicing: I actually didn't sluice much at alll, we mostly creviced. We found the gold to be small, stubborn, but consistent. Sort of like a mule, IF you can find areas where it was trapped in gravels or clay near the water.
Here's a picture of the cleanup I did. No flakes, only fines, but the fines were somewhat chunky which was encouraging. Best of luck!