The Skagit above Marblemount is only open up to Bacon Creek in March/April and there is no boat launch at Bacon Creek along with very (I mean virtually none) limited foot access from Bacon Creek all the way to Marblemount. The Skagit is a big river along the size of the middle and lower Potomac; therefore, a guide is not a bad idea.
Mike Kinney, Ed Ward, and John Farrar are the best fly guides working the Skagit and Sauk. Jack Cook is another good one, and our own Northfork16, Ryan Petzold, aka "Sparky" is an up and coming one. Come out and enjoy the beautiful Sakgit Valley, which I call home.