The whole canyon was wiped out by the fires and subsequent debris flows, I would be surprised if trout survived above the falls, since there seems to be no sign of them below. I fear the upper part of the creek got boiled away in the Piru/Hopper fires, the canyon is quite narrow and water not real deep above the falls. Like I said, I last fished the area in 1976, well before it was designated to possibly support steelhead migration.
John