It is very good. As far as I know, the access to the river from the Keno Dam down to J.C. Boyle Dam is completely public on at least one side. Additonally, since all free-flowing water bodies in the state of Oregon are publically accessible up to 15' past the high-water mark, you shouldn't have any problems.
Normally I wet-wade in shorts and tennis shoes, but the water was so high this year that I had to use waders. Still, about 60% of the areas I fish are wade-able as long as you pay attention. There are 20' deep holes in a few places, so use common sense, and look before you leap.
There is a lot of wading access within the first mile or so below the Keno Dam.