Try some of the lakes up on Sawtooth ridge. (up Gold Creek and a couple other roads/trails) You will need to hike in. Martin lake, Eagle lake, Cedar lake. All should have fun, small trout fishing! Perrygin, Alta, and a few others are in the area too! Check out
www.washingtonlakes.com and go to Okanogan Co. for a list of the well known ones. There is also the Chewack (Chewuch) river. And Cutthroat lake (hike in from trailhead towards Washington Pass) has nice fishing for...you guessed it, little cutthroat. Check the regs, but there are dozens of small creeks that flow in and could be excellent action for small trout.Goodluck!