Dennis, the chehalis is the lat place I would take new fishers with little river experience. That river reacts to rain quicker than any river I know. I have seen it rise 2 feet in no time at all...these beaks tackle boxes started floating away cause it came up so fast! And where would you suggest he take these students on the chehalis. I spoke with the hatchery yesterday and there was ZERO water coming down in front of the hatchery...so you are suggesting a group of 8 students walk in on the bible camp...sounds like trouble to me.
If you are set on going out OTH, my safest bet would be something like the harrison but I dont know how hard its running or its clarity. Instead of float fishing wool, I would recommend you get some spinners, spoons, and colorado blades....do some casting from shore...good for coho and chum. Right at the #7 crossing of the harrison, there is a ton of room on all 4 corners of the bridge for a big gang like yours.
Maybe I could help out...I snorkel the cap lots and have a ton of spinners and spoons, I could supply you some opposed to having to send your group out to buy spoons at 4-5 bucks a pop.
email me if you're interested. (icon in the left side of this box).