A good friend that I knew that had worked with both wild and hatchery stocks was pretty adamant about straying. Wild Steelhead stray all over the place which was natures way of adapting but hatchery Steelhead not nearly as much as long as you released the smolt from a location that could capture returning adults. Salmon similar but stream conditions always shake things up. Low water Salmon will improvise and just plain find a place to spawn, high water move into an area that meets their needs.

When working in forestry years ago I was in a unit that had zero salmon spawning habitat. When going down a ravine in a rather heavy rain storm I was stunned to find a Coho beating its way up a foot wide run off channel. We have a tendency to think we know why fish do what they do when the fact is they run on pure instinct and frankly improvise a lot.