SE Alaska. I've experienced it. Next to Russia, probably the most pure runs of steelhead. Lucky for them, the fisheries are pretty inaccessible unless you have a few hundred grand to invest in a long range boat from the nearest marina, as well as the gas to do some exploring. Because I know the few who are doing these fisheries sure as hell aren't going to tell you where to go unless you pay them $4-5k for a week of guiding. And even then, they'd probably blindfold you if there was any indication that you had access to a capable boat.