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. To be a member of the tyee club these criterea must be met:
1) It must be caught out of boat which is rowed (no power)
2) It must be caught on line no more than 26.25lbs breaking strain
3) Qualifying fish must be taken from the waters of Discovery Passage bounded on the north by Seymour Narrows and on the south by a line extending due west from Cape Mudge.
4) Rod used must be between 6-9 feet
5) only single action reels are allowed (I believe)
6) Fish must be 30+ lbs
7) A fish must pass a certification by a judging panel to be considered a tyee.
There are many other rules but basically the whole tyee thing originated on the island from the Tyee Club (
http://www.tyeeclub.org/rules.htm)
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.