From another thread...this was posted by Spawn Sack
"if you are fishing a trout set up and could convince a CO that you are not targeting steelhead, then you would be fine without a steelhead tag. Since it sounds like you will be targeting trout mainly but s/h too, I WOULD buy the s/h tag, then if you hook into a hatchery s/h you can keep it. Personally I would buy the tag regardless as the $ goes towards conservation, and you would not have the potential problem of not having the tag and trying to convince a CO that you are only trout fishing."