4Salt,

You are very knowledgeable and your information about how to tell a steelhead from a salmon is helpful and appreciated.

As to the number of rays on the anal fin, however, you have it backards.

In the words of Frank Haw, a highly respected biologist and expert in fish anatomy:

"Pacific Salmon can be seperated from trout by counting the soft rays on the anal fin. A count of the unbranched bases of the anal fin rays will be less than 12 for trout and char and 12 or more for Pacific Salmon."

11 or less = trout or char
12 or more = pacific salmon

As you mentioned trout and char are essentially white inside their mouths while salmon have dark pigmentation.