Fly Fishing Insider Podcast
On the upper Colorado River, a triple nymph rig is the workhorse: a Pat's Rubber Legs trailed by a Baetis nymph and an RS2 emerger, run four to five feet under a BB split shot. On the Blue River tailwater in Silverthorne, mysis shrimp patterns lead the rig instead.
Colton McLaren is a Colorado fly fishing guide working out of Kirk's Fly Shop in Grand Lake, running float trips on the upper Colorado River and backcountry trips in Rocky Mountain National Park.
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What nymph rig does a Colorado River guide use most?
The default on the upper Colorado is a triple nymph rig: a Pat's Rubber Legs on top, a Baetis nymph in the middle, and an RS2 emerger on the bottom, fished roughly four to five feet deep with a BB or number four split shot set just above the rubber legs. In summer the alternative is a dry dropper - a Chubby Chernobyl or caddis on top with a Pat's Rubber Legs or pheasant tail underneath. Streamers come out mainly with experienced anglers, since a big articulated streamer passing a client's head is its own hazard.
Why do Blue River rainbows in Silverthorne get so big?
The Blue River runs out of the bottom of Dillon Reservoir, and the dam pushes mysis shrimp out with the water. That constant protein source is why the tailwater section near the dam produces rainbows in the 27 to 28 inch range, with larger fish occasionally taken. Colorado has a handful of mysis tailwaters - the Taylor and the Frying Pan below Ruedi Reservoir among them - and they all share that pattern.
What is the difference between a live mysis pattern and a dead one?
There are two distinct styles of mysis pattern and they are not interchangeable. Clear epoxy or UV resin bodied mysis represent dead shrimp, which is what you find miles downstream of the dam by the time the shrimp have died off. White marabou mysis represent live shrimp and belong right below the dam, where the shrimp are still coming through fresh. On the Blue River, a mysis rides as the point fly to get attention, with midges or a Baetis trailing below it.
How do you fish a big freestone river like the upper Colorado on foot?
The upper Colorado has a reputation as a float-only river, but it wades well if you stop trying to fish the middle. Look for braids and side channels that split off the main stem and slow the water down. In high summer flows of 2,000 to 3,000 cfs, trout will not sit in white water burning energy - they sit on the edges, and brown trout tuck under cut banks. Nine times out of ten the fish come from the first three feet off the bank, so fish the edges before you step in. A wading staff and cleated boots are worth carrying at any age.
Should you rig your fly rod before you get to the river?
Colton McLaren argues against arriving pre-rigged. A freestone river changes day to day - blue-winged olives one day, Baetis the next, nothing but midge larva the day after - so rigging in the parking lot means fishing yesterday's guess. Have a rod strung and something tied on, but wait until you can see what is hatching and flip a rock before you commit to a rig. The first two or three casts into a good lie are often the ones that produce the best fish of the day.
What should you do after hooking a big fish in fast water?
Have a landing plan before the fish eats. Start fishing where slack water is within reach so you can apply side pressure and steer the fish into a pocket you can actually net it in. Anglers usually plan around what to avoid - grass, logs, boulders - but the more useful question is where you want the fish to end up. A wild trout that gets into fast current is very hard to recover, and chasing it downstream is how people fill their waders.
How does tightline nymphing work on a pressured tailwater?
On the Blue River in Silverthorne, McLaren gets his best results with no indicator at all - not a euro mono rig, but fly line with a nine-foot leader held tight, the way anglers used to swing soft hackles. He runs the rig past a fish he has already spotted, feels for resistance, and sets in the same motion that begins the next cast. Heavily pressured tailwater trout barely move to eat, opening and closing their mouths without shifting position, so the fly has to arrive on their nose rather than near them.
Key takeaways
- On the upper Colorado, run a triple nymph rig - Pat's Rubber Legs to a Baetis to an RS2 - about four to five feet deep with a BB split shot above the top fly.
- Match your mysis pattern to your position: marabou (live) shrimp right below the dam, clear epoxy (dead) shrimp miles downstream.
- On a big freestone, fish the first three feet off the bank and the side channels before you wade toward the middle.
- Do not rig up before you see the river; look at what is hatching and flip a rock, because freestone conditions change day to day.
- Pick a starting spot with slack water nearby so you have somewhere to steer a hooked fish before you hook one.
- On heavily pressured tailwater fish, a tightline presentation with no indicator puts the fly close enough for trout that will not move to eat.
