That would be my take on Steelhead as well. I don't see them jumping until they have been hooked. Once hooked, they will jump more than most salmon. Every now and then they will fool you and just dive to deeper water, but most the time they seem to go airborne!
As to why Salmon jump in rivers, that is a great debate that comes up online a couple times a year. There are different theories. If the loosening of egg sacks is true, this would make sense why Steelhead don't jump. From my understanding, they will stay in the river quite awhile before spawning which would give time for their bodies to get ready. If for one still believe the reason Salmon jump is because they don’t have a middle finger! wink: