Piper the Washington Dept of Natural Resources has a map on their website that shows what rivers or portions of them are considered navigable. Go to their site and use their search to look for navigable waters....it'll take you right to it. You'll find that very few waters are shown as not navigable but on the other hand you'll also find many rivers are not shown as their navigability is undetermined....such as the Quilcene.

If anyone is really interested in what state laws say about this issue alls you have to do is go to the the state legislatures website. There you will find the current RCW's, WAC's and even the state attorney generals written opinions. Simple search of all 3 on that page will provide you with a lot of info. Be sure to read the definitions of what "navigable waters" are under Titles 79, 88, and 90 of the RCW's. THe attorney generals opinions will also speak to the jurisdiction of the Federal government. You'll also see an AG opinion on the the issue of undetermined navigability...specifically North River....very interesting opinion.

Sorry I meant the Carbon ...not the Cascade.