people talk about trout fishing (particularly the novice), visions
of the rainbow are evoked. The rainbow has been described as the "true
American trout" because of it's origins in the Pacific Northwest.
This brings argument from scientific types who study such stuff, but
most of us don't care about things like that. Most of us think excitement
when we think rainbow.
The rainbow has spunk. They don't stay with the stream bottom like
brown trout, or hide in quiet backwaters like the brook. Rainbows
are to be found in the open, faster waters, where they tend to feed
at the surface more often than other trout. They are open, up front
and honest, and for that reason we think more respectfully of them,
and they are usually the most fun.
While the North American rainbow trout is native to westward flowing
Pacific Coast rivers, they have been introduced to many streams worldwide.
Rainbows are the most easily cultured and adaptive of all trout and
are thus included in most stocking programs. Rainbows had been introduced
in forty-one states by 1900.
Markings and Coloration
Stream-living rainbows are easy to identify. Their upper bodies are
heavily covered with black spots, a pattern that extends over the
tail. Their backs range from light to dark olive, the abdomen is white
and there's a characteristic reddish pink band along the lateral line,
a color that usually extends forward over the central portion of the
fish's gill covers. There are no red or yellow spots.
As mentioned earlier, rainbows are the most adaptable of all trout
and can tolerate a wider range of temperature and conditions than
other trout. Rainbows can survive temperatures approaching 32 degrees
Fahrenheit and some can survive in water as high as 83 degrees, though
they prefer a range of 55 to 70 degrees.
[ Back to Top ]
Range and Habitat
The feeding habits of rainbows is generally similar to that described
for brown trout. They are usually drift feeders--holding stationary
positions in the current, usually in relation to a rock or other current-breaking
Rainbows usually pre-fer faster water than other trout, and there
is some research data indicating that they will hold feeding positions
in slightly faster water than that used by brown trout. Rainbows also
often hold themselves higher in the water column than brown trout,
which usually orient themselves close to a rock or other bottom object.
Rainbows apparently find the same sort of security under a choppy,
broken surface that a brown trout finds by hiding under a stump. Rainbows
are much less oriented to physical, overhead cover than browns. When
hooked, larger rainbows don't usually run for over-head cover as larger
browns do, but rather just run and run and run in their attempt to
evade the difficulty of being hooked. These trout are also almost
unique among trout in usually jumping one or more times when hooked,
a characteristic that seems to be just as prevalent among large rainbows
as among small ones.
As with other trout, growth rates in rainbows are variable, depending
on habitat and available food supply. For example, one-year-old rainbows
will average 4 or 5 inches long; at two years approximately 6 or 7,
and 9 inches long at three years. The maximum age reached by most
rainbows is about seven years and, if they drift-feed, can weigh 8
pounds or more.
A final thought...
The demonstrated ability of rainbow and other trout to learn, remember,
and to act as individuals different from the norm is central to the
whole sport of fly fishing for trout. These abilities have much to
do with why trout are selective in the first place and why, as a result,
there is no one trout fly that works for all of the trout all of the
The restoration efforts of Park resource managers have led them to
closing some streams and tributaries
to all fishing, and ensuring natural barriers such as waterfalls are
adequate to prevent the brown and rainbow trout from migrating upstream.