Most Washington rivers, especially those on the west side of the Cacades are
high-gradient streams with low mineral content. The resulting environment
has little insect life and consequently very little food for resident trout.
What food is available must be shared with immature salmon, steelhead and
sea-run cutthroat in their pre-migratory phases. At one time there were
small populations of resident rainbows and cutthroat in many western
Washington streams; they were slow-growing and have only rarely been able to
withstand even the lightest fishing pressure. There are still a lot of
people who insist on fishing for "rainbows" when, in fact, they are catching
steelhead parr and smolts.
The situation in eastern Washington is a little different and some rivers,
like the Yakima, Methow and Stehekin, have sufficient mineral content to
support large insect populations and thus self-sustaining populations of
trout that grow to decent size. These rivers can't, however, come close to
producing the size or numbers of trout that the rivers of, say, Montana do.
A guide once told me that in thirteen years of full-time guiding on the
Yakima he could count on one hand the number of actual twenty-inch trout
that he had seen. With the large-scale re-introduction of chinook, coho and
steelhead to the Yakima, even its trout fishery may become a thing of the
past.
Some of the state's best trout fishing, at least in western Washington, is
for sea-run cutthroat. These anadromous cutthroat, unlike salmon and
steelhead, continue to feed after re-entering fresh water and their
aggressive habits and saltwater-tempered strength make them a
highly-desireable quarry for the fly angler whether in saltwater or in the
rivers.
