Fly Fishing the Spring Runoff in Utah

Fly Fishing the Spring Runoff in Utah

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Every year, as the snow melts, I go through the same transition of breaking down my winter gear and putting skis, boots, and heavy coats into the depths of the closet. I know I will probably have to get them out again, even though it has been warm for a couple days and I think spring is here to stay. There is still snow in the mountains and it freezes more nights than not, but I can’t stop my brain from wandering to larger flies and trout on the water’s surface sipping bugs bigger than a grain of rice.

My experience tells me I am kidding myself and to slow down. Blue-winged olives will begin to hatch on most rivers, but the spring runoff isn’t in full swing due to the low nighttime temps. I have been bundling up and fishing midge hatches for too long. I need a fly fishing fix.

In years past I would hit the same spots as everyone else – tailwaters close to the dams – and try and compete with the same people having the same spring fever fishing needs. I’ve recently made some changes to that mindset, though, and I have enjoyed changing it up before and during the big melt.

“As the water temperature drops below 40 degrees, the trout tend to become lethargic and slow to react. You can catch fish in these cold temperatures, but it takes patience and the right flies, with the right presentation. ”

The Right Fly, With the Right Presentation

I remember trekking through snow as a youth to fish my favorite holes and coming up blank. At times I would see fish but seldom, if ever, would I hook or land one. This just reinforced the facts about fish and water temperatures. Water tends to be warmer in tailwaters during the winter and cooler in summer than the headwaters of streams and rivers in the mountains. This is one reason that tailwater trout are typically larger: water temperature has a lot to do with fish activity and growth. As the water temperature drops below 40 degrees, the trout tend to become lethargic and slow to react. You can catch fish in these cold temperatures, but it takes patience and the right flies, with the right presentation.

My most recent example of this phenomenon was on April 9th of this year. The water temperature was 38 degrees, nighttime lows were 28, and daytime highs only hit the low 50s in the mountains. I started with a streamer and had one super slow take, but lost the fish seconds later. I switched my fishing partner over to a nymph rod and threw on a go-to for spring runoff fishing, the San Juan worm with a trailing caddis nymph on an inline setup. After about 20 minutes of the same drift I began thinking that we were wasting our time when my friend suddenly hooked up. Then hooked up again and again during the next 15 minutes, landing seven fish. Once we found the fish our action was great, even in the cold water.

a small fish held out of the water

Be Persistent

I am starting to really enjoy the challenge of early season, high-mountain trout streams. Reading the water is important when it’s cold, but you must keep in mind that the trout will not move very far to eat. Adjust your fly depth, drift, and presentation before changing flies. I have found most cold-water runoff trout will eat a small San Juan worm, but I usually follow it with a caddis or mayfly nymph. Be persistent and fish thoroughly. In many cases a fish will eat the bug only if it is right in front of its nose.

Another favorite strategy of mine is to throw a small wooly bugger, and in some cases I dead drift it under an indicator like a sculpin. Some fish will move a little more for a big meal. Sculpins are popular trout food since they stay close to the bottom and dart from rock to rock.

“I have found most cold-water runoff trout will eat a small San Juan worm, but I usually follow it with a caddis or mayfly nymph. Be persistent and fish thoroughly. In many cases a fish will eat the bug only if it is right in front of its nose. ”

Be Cautious and Time Your Fishing Wisely

Once the weather warms a bit more, the snowmelt increases, and water levels rise, so it can become dangerous to wade. It is good practice to use a wading staff if you are unsure; otherwise, try and stay on the bank.

The increase of snowmelt water can also drop the temperature again. Use a thermometer and see what the temps are where you are fishing. I usually like to be on the water early. However, during early springtime, I lean towards late morning and afternoon. This gives the sun time to warm the air, and that can prompt spring hatches of caddis and mayflies.

a sky view of a river with snow on the banks

Bottom Line

Often you can start a spring day with freezing temps and by midafternoon you are fishing in the 60’s. Hatches this time of year can be sporadic at best. The bottom line is, you will not catch a fish on the couch – so head out and give the cold water a try. It is an amazing time to be in the mountains. The rivers are waking up from the long cold winter and the trout are becoming active. Take the time to sit on the bank and enjoy the mountains of spring with the rushing water, fresh green growth, and the flashy trout just waiting for your next cast.

Travis Jay Vernon, Fly Fishing Guide