Utah's trout fishing is anchored by exceptional tailwaters. The Green River below Flaming Gorge Dam in the canyon country of the Uinta Basin is one of the premier fly fishing destinations in the West - cold, clear, nutrient-rich water that supports some of the highest trout densities anywhere. The Provo River, tumbling out of the Wasatch Mountains below Deer Creek Reservoir, offers another outstanding tailwater experience within an hour of Salt Lake City.
What unites Utah's best trout water is an emphasis on small flies and precise presentations. Midges and San Juan Worms dominate the tailwaters year-round, while Blue-Winged Olives provide the best dry-fly opportunities. These five patterns are the foundation of any serious Utah fly fishing kit.
Ranked by versatility across rivers, seasons, and trout species.
Pattern #1
Sizes#10 – #14
ColorsRed, Pink, Tan
SeasonYear-round
TechniqueDead drift under indicator
The San Juan Worm is the anchor pattern on both the Green River at Flaming Gorge and the Provo below Deer Creek - two of Utah's most productive tailwaters. Aquatic annelid worms are an important food source in the rich, silty environments created below dams, and Utah's tailwater trout have learned to seek them out year-round. Red and pink in #12 are the standard starting colors.
On the Green River's A section, the most productive near-dam stretch, the San Juan Worm fished as the point fly in a two-nymph rig accounts for an enormous percentage of the fish caught throughout the season. It doesn't look like much, but it produces with remarkable consistency.
Pro Tip: On the Green River, try a two-worm rig in different colors - a red San Juan Worm on the point and a pink or tan worm as the dropper. This doubles your coverage of worm colors and helps determine which the fish prefer on any given day. When you find the color, fish two of the same until the bite changes.
Pattern #2
Sizes#20 – #26
ColorsBlack/Silver, Red/Silver, Blue/Silver
SeasonYear-round
TechniqueIndicator nymphing, Euro nymphing
Utah's tailwaters are fundamentally midge fisheries. The cold, stable water below Flaming Gorge and Deer Creek Dam creates perfect chironomid habitat, and the trout's diet reflects it - midges in all life stages are available and consumed throughout the year. The Zebra Midge, Disco Midge, and Mercury Midge are the three patterns that cover the most situations.
Size is critical - Utah tailwater fish see enormous fishing pressure and will refuse midges that are even one size too large. Carry sizes #20 through #26, and don't hesitate to drop to the smallest sizes on heavily pressured sections. Use fluorocarbon tippet in 6X or 7X for the most natural presentation.
Pro Tip: On the Provo River's canyon section, try Euro nymphing with midges instead of an indicator. The tight-line approach gives you much better contact with small, light flies and helps detect the subtle takes that Utah's educated trout often give. A 10–11 foot rod with a thin sighter instead of an indicator keeps your presentation natural in the Provo's moderate current.
Pattern #3
Sizes#18 – #22
ColorsOlive body, Gray wing
SeasonMarch – May, September – November
TechniqueDead drift, reach cast
Spring and fall BWO hatches on the Green and Provo rivers provide Utah's best dry-fly opportunities. On the Green River, overcast autumn days from September through November trigger dense BWO emergences that bring large rainbows and browns to the surface - the best surface fishing of the year for anglers used to nymphing Utah's tailwaters. A #20 Parachute BWO on 6X tippet is the standard approach.
Spring BWO hatches on the Provo in March and April can also be excellent, particularly in the canyon section where fish are accessible and the hatches are visible and predictable. Watch for overcast, cooler afternoons - these conditions consistently produce the best emergences.
Pro Tip: On the Green River for fall BWOs, position yourself on the inside bends of the river where current slows and emerging duns collect. The trout hold in the slower water adjacent to the main current during the hatch - easier positions than the main flow and more accessible for careful presentations with light tippet and small flies.
