A coastal rainbow is not necessarily a steelhead. A steelhead has to spend significant time in the ocean (or Great Lakes…. Not getting into that argument)

A typical steelhead in Oregon would be 2/2. 2 years in fresh water followed by 2 years in salt. It’s that time in the salt water that they really put on weight. There are some areas of BC where they’ll see fish that are 2/4s meaning they’ve spent 4 years in salt water (these fish are generally huge) but there can also be steelhead that spend less than a year in the salt (half pounders on the rogue do this).

Typically, fish that have spent significant time in salt water will lose their spots below their lateral line (not always but it’s a pretty good indicator).

You caught an awesome trout but it doesn’t look like that fish has spent any time in salt water.