There are no motors allowed at all that includes electric motors. My friend knows first hand with the ticket he got for using a electric trolling motor at barney.
Yes there is a lot of access to the river. The water is nice and warm so you can walk the river in shorts and a t-shirt also it helps keep you away from the rattle snakes hidden in the bushes along the river.
Out around the fossil beds and down river to spray has to be the best place to catch smallmouth bass if you don't care how big they are, early in the spring the bigger (2lbs to 4lbs) ones bite if that is what you are looking for. I have gone through a pack of tube baits and a half pack of...
A good way to get the rainbows schooled in front of the hatchery pens is to use a dry fly for an indicator and drop off of that a zebra nymph. But the secret is grab a hand full of the pea gravel and toss it in on top of the school as the fly passes over, they go crazy hitting the surface...
I fish the south side of it from HWY 47 up stream to almost behind stimson lumber mill, and it is all private property owed by my family. You can google it since you seemed so surprised.
The average fish I get is about 8-12 inches, but there are times when I will get 4 or 5 cutthroats being 15-18 inches all in one visit and at only couple a different spots.
The best tributary of the tualatin for fishing is the scoggins creek by far. I catch fish every time I go, the biggest one being a 20 inch cutthroat a couple years ago.