Yeah ... 1) where in Jay Cooke were you talking of putting in? and 2) there is a fairly big dam near the southern end of the park.

There are large sections of the river in Jay Cooke that are just not navigable. In fact the river near the upper dam is pretty damn tricky, they have kayak races there a few times in the summer, coordinated with water releases from the dam. I just would not do it in a canoe ... unless you want to die.  There is a canoe-able stretch, just above the lower dam, and a place to put in ~1/2 - 1 mile from said dam. You can paddle upstream a few miles until you hit the never ending rapids. It's a nice paddle and worth a relaxing day trip, you'll go right by the old MN Power Hydro plant, a few places to stop and eat lunch and swim if you want. Have seen otter in that area. The most traffic has been one or two small motor boats out fishing.

Did St Louis river from Little Swan to Floodwood once. You could start further up. After Floodwood, river gets bigger.

Under no circumstance should anyone try and run any of the rapids on the lower section of the St. Louis River (below the hwy 210) in a canoe, kayak or boat of any sort unless you have class IV+ paddling skills and crew of experienced boaters with swift water safety knowledge. Potential for serious injury or worse is high.