Chinook Salmon are the most desired salmon to catch by avid fisherman because of their size and strength when near maturity. If you ask a coastal guide how many fish he has, he will usually tell you based on the number of Chinook, not on the other kinds of salmon he has caught. Chinook are considered small when in the 5-15lb range. When they get larger than this they usually become more active and of course bring enjoyment to any avid angler.
3-5 year Chinook are the most common and will be mostly be 20-50 lbs near maturity. 
Chinook usually like to dive deep when taking line, so if they are caught near the bottom, they often won’t run as far. The closer to the surface they are caught, the better the fight will be! You will see the best reaction when caught in narrow shallow channels. In this case the angler better be ready to turn the boat where ever needed. In most cases Chinook are caught in deeper water unless they are following they migratory route back to the river to spawn. During the feeding years Chinook are often caught in the 100-200 ft range.
Amazingly Chinook will usually take the same route back to the river they took as a juvenile salmon. This often means they are up shallower and not in areas some people expect. Chinook mostly feed on herring, anchovies and pilchards depending on whether they are in Alaska, British Columbia or Washington. The Kenai River is known for the largest Chinook in the World. In recent years it has become known as “combat fishing” and fishing has not been as productive. The reputation however, will keep people coming for many years. Sitka Alaska is a good place to catch Chinook in the ocean and provides a good alternative for those heading north. Here Chinook are generally in the 15-50 lb range.
British Columbia also boasts some great Chinook salmon fishing. The west coast of Vancouver Island along and the Queen Charlotte Islands generally have very good Chinook salmon fishing in the 15-50lb range with a few Chinook being taken larger. “Tyees” are known as Chinook over 30lbs.