the-fall-spawning-season-has-arrived (1)

The Fall Spawning Season Trout has Arrived

Fall has arrived here in the mountains of Colorado, and with all of the leaves changing color comes another less noticeable transformation. Many of the trout that live in our rivers and streams have begun to spawn. While rainbow trout and cutthroat trout reproduce in the spring, brook trout and brown trout wait until the fall.
The dropping temperatures and the shortening days trigger the fish to begin their reproductive process, which for many of them, starts with a long migration upstream. Although the trout here in Colorado are completely landlocked, most of them still swim upstream to smaller tributaries and creeks to spawn. During this journey, the mature males often become darker in color and develop a hooked lower jaw called a kype.

The Trout Spawning Process

The actual trout spawning process begins with the female trout digging a nest (or redd) in
a shallow gravel covered section of the riverbed with just the right amount of current.
She fans her tail rapidly against the small rocks to remove the debris and clean the redd
before laying her eggs. Once her eggs are laid, she will move to the upstream side of her
nest and allow one or two male trout to fertilize the tiny eggs before she covers them
up with more rocks. When the eggs are fertilized, the trout abandon the redd and return
downstream to their normal territories. The eggs will remain in the nest for most of the
winter until rising water temperatures and longer days signal the next generation to hatch.

How Anglers Can Help

The two best ways we as fly fisherman can help the fish along are to stay away from
the redds, and to limit our trout fly fishing at the confluences and small streams where the large
populations of spawning fish are holding. Also, please avoid fly fishing for trout that are
actively spawning on redds as they are very vulnerable and not all challenging to catch.

Avoid the Brown Trout Redds

Most brown trout redds are easy to see once you know what to look for. Often times
they are in slower moving water where the river bed is made up of small rocks or gravel.
The rocks and gravel inside the redd will appear cleaner and lighter in color than the
rest of the area. One fly fisherman can wipe out thousands of trout eggs with just a few
misplaced steps. While fishing during the spawning season, we need to be more careful
than usual not to step on these fragile areas.

Steer Clear of the Confluences

Colorado Parks and Wildlife has instated limited closures of known trout spawning
grounds on the Roaring Fork and Colorado rivers. These areas are at the confluences
where small streams meet the main watersheds, such as the closure at Grizzly Creek on
the Colorado River. Although not all of these areas are closed to fishing, fly fisherman
can go the extra mile and stay away from them until the trout are done spawning.

Fall Fly Fishing in Colorado

Fall can provide some of the best fly fishing of the year. The scenery is beautiful, the
bugs are active, the water is cool again, and the fish are healthy. It is important, however,
not to inhibit our local trout’s reproductive process while we enjoy this epic season.
Remember to visit Vail Valley Anglers to get answers to your fly fishing questions and to load
up on your fall fly fishing gear essentials.

Andy “Otter” Smith, Guide and Content Writer