Stlhdh2o -
The male and female steelhead behave differently following spawning. Typically the females dig its redd (sometimes several) over the course of a day or two. She is attended by one or males with much fighting between the various males with the larger generally becoming the dominate one. Immediately after spawning the female drops downstream into slower water. It is here that she begins the recovery process. How long she remains in the river is influenced by water conditions - under low water they may remain in those slow holes for weeks where they bright to near sea-bright condition and may begin feeding some. That explains why they are so catchable and illustrates the different between trout/spawnout and steelhead fishing. In their recovery their ovaries shrink down to about thumb size and contain next years eggs (if you look at the eggs from an unspawned females closely you will see small pale dots among the eggs - those are next years eggs). With a silver condition, small eggs they are often confused with summer-runs (of course there is little or no fat). With high water conditions the females are flushed quickly out of the system and do their recovery in the salt. That why you tend to see more spawnouts during low water conditions.
The males behave differently in that following spawning the continue to look for additional spawning opportunities. Some remain in the system until all spawning is done. That is why those June fish are mostly males and why in the late spring/early summer the dead steelhead you see are nearly all males. Occassional the males hanging out in the small tribs to spawn may get trapped by low flows and can't or will not level the creek. Those are the odd spawnout that is see in the late summer/fall after a rain. I have seen winter spawnouts in the Skagit system as late as late October.
Survival of the spawnouts vary between river systems and depends on the conditions after spawning. High water springs seem to flush the fish out quickly leading to higher survivals. The % of the returning fish that have previously spawn in local waters vary from 2 to 25%. In some populations at the extreme ends of the species range the majority of the population may have spawned before.
Our winter fish spawn every year once they reach sexual maturity. They fish don't grow much between spawning. A pre-spawn female might weight 8# before spawning and only about 5# after spawning. Much of the feeding following spawning will go to recoverying that lost weight. That is why repeat spawners are only slightly larger than they were the first time. Interestingly the repeat spawning females have more eggs than the first time spawners. For example on the Sauk the first time spawning 2-salt females (8 to 10#) had about 5,000 eggs/females, the 3-salts (12 to 18#) had about 6,500 eggs/females and the repeat spawners (9-14#) had 8,000 to 12,000 eggs/female.
While most fish only spawn once occassional individual fish may spawn as many as 4 or 5 times.
Hope I could the name right this time and this helps.
Tight lines
Smalma