Question about the Snoqualmie

So, while traveling from Yakima to my parents' house in Skagit county we passed through Fall city and stopped at the little roadside park for a stretch break. The water is very clear right now and not very fast, and we were able to see fish on the bottom- at least when they would move.

I am wondering what they might be as they looked pretty big and it's too early for salmon. Steelhead maybe? I didn't break out my rod since I didn't know what the regs are for that part of the river or if it's even open. We saw tons of people swimming and floating further up the river, but there was no one near us and the fish. If we had more time I would have jumped in with my mask and snorkel to take a look.