OMJ has it right. The Stillaguamish, especially the North Fork, has plenty of access. Driving east of Arlington on 530 takes you past many places where you can get to the river and, once you're there, you can easily wade up or downstream for long distances without hindrance at summer's flow levels. Some obvious access spots: Twin Rivers Park (just across the bridge out of Arlington) the Lime Quarry (127th Ave., just beyond Trafton), Cicero Bridge, Oso (at the mouth of Deer Creek), Hazel, and Fortson Mill Rd. The South Fork and the main River may not offer equally obvious access points but the usual technique of driving around, looking for parked cars and doing a little exploration on foot will pay dividends.