Tyee is now a bit of a bastardized term (as it is in this case). Technically a spring can only be called a tyee if it meets a bunch of different qualifications.
Some fishermen here now apply the term to a large spring, but if you were to follow the history, traditions, and rules for calling a fish a tyee, then you know it is really a borrowed and incorrect label.
quote from the Tyee Club website:
The Tyee are Chinook salmon, 30 pounds or larger.
This is even stated in the fishing regs:
Average-size chinooks are know as springs in B.C. Those over 13.5 kg are called tyees.
A chinook 30 pounds + desereves it's own name as they are truly a marvel. Congrats on the
tyee legend