Have never heard of sturgeon on the Sky or Skagit but have always had excellent luck on the Chehalis. fished adjacent to the boat launch in Cosmopolis 3 weeks ago (43 incher) and Friends Landing last weekend (47 incher).
When not chasing salmon in the fall or playing in the Skookumchuck in the winter I can be found exercising my shoulders and back on the Chehalis. If interested I have a lot more info for you on this one.