I seen a couple landed last week, I only caught reds while out there. I went out last night and it was slow, probably 6-7 people fishing and I spent about 3 hours there. While I was there nothing was landed spotted about 5-6 rollers.
I caught one silver, about 5#, and one red in Jim creek proper, not Knik, on Sunday. We fished all day and had a great time but didn't exactly deck load the boat. Saw lots of fish but mostly reds, I'd guess 10 to 1 reds to silvers.
Read a post on AOJ that said access road where you leave the trees was flooded 8 /14 AM.
They said you could drive if you knew where the high route is (i.e. the shallowest route).
Fishing area flooded and unrecognizable (but still there).
Based on this info, I'll answer my own question for the benefit of others:
The access road where you leave the trees starts to flood when the river stage reaches about 11.5 feet.
For easy access only go if the river stage is 11.0 ft or less.
Ideal conditions (based on my past experience) are from 9.5 ft to 10.5 ft