Bonneville Cutthroat Trout Guide

Hatch timing snapshot

Use this quick read to align the species profile with the insect activity that moves fish.

Match the hatch section headings to the timing notes in this profile.
Check flows and water temperature before you choose your approach.
Confirm life-stage activity, then dial in size and presentation.

Description

The Bonneville Cutthroat Trout (Oncorhynchus clarkii utah) is a native subspecies of cutthroat trout endemic to the Bonneville Basin, which includes portions of Wyoming, Utah, Idaho, and Nevada. Named after Captain Benjamin Bonneville, this beautiful fish is distinguished by its vibrant coloration and distinctive markings.

Bonneville cutthroat are characterized by their golden-yellow to olive-brown coloration with a distinctive red-orange slash under the jaw. They have large, irregularly shaped spots concentrated toward the tail, with fewer spots on the head compared to other cutthroat subspecies. During spawning, males develop brilliant orange-red coloration along their sides and gill plates.

This subspecies has adapted to the unique conditions of the Bonneville Basin, including alkaline waters and temperature extremes. They are an important indicator species for ecosystem health and represent a critical component of Wyoming's native fish heritage.

Habitat

Bonneville cutthroat trout occupy diverse habitats within their historic range:

Stream Systems

Found in cold, clear mountain streams throughout western Wyoming, particularly in the Bear River drainage and tributaries of the Green River system. They prefer streams with clean gravel substrates, abundant cover, and stable flows.

High-Elevation Waters

Thrive in alpine and subalpine streams and lakes above 7,000 feet elevation, where water temperatures remain cool and competition from non-native species is reduced.

Preferred Conditions

Bonneville cutthroat prefer water temperatures between 50-60°F (10-16°C) and require clean, well-oxygenated water with stable flows. They are sensitive to habitat degradation and competition from non-native trout species.

Conservation Waters

Many populations are now found in headwater streams where they have been isolated from non-native species through natural or artificial barriers. These conservation populations are critical for the subspecies' survival.

Behavior

Bonneville cutthroat exhibit behavioral patterns adapted to their native environment:

Feeding Behavior

Opportunistic feeders that consume aquatic insects, terrestrial insects, and small crustaceans. They are less selective than some other trout species and will readily take a variety of fly patterns. During insect hatches, they feed aggressively at the surface.

Seasonal Patterns

Spring: Active feeding and spawning activity (April-June), excellent dry fly fishing during mayfly hatches

Summer: Seek cooler water in shaded pools and riffles, morning and evening feeding peaks

Fall: Aggressive feeding to build energy reserves, excellent streamer and nymph fishing

Winter: Reduced activity but still catchable in deeper pools with slow presentations

Spawning

Spawn in spring (April-June) in small tributary streams with clean gravel. They are less wary than some other trout species during spawning but should not be targeted on redds.

Movement Patterns

Generally less mobile than rainbow trout, with most fish remaining in relatively small home ranges. Some populations exhibit short spawning migrations to tributary streams.

Fishing Information

Bonneville cutthroat fishing offers rewarding opportunities for anglers seeking native trout:

Fly Fishing Techniques

Dry Fly Fishing: Effective during mayfly, caddis, and terrestrial hatches. Bonneville cutthroat are less selective than other species and will often take attractor patterns.

Nymphing: Dead-drift nymphs through runs and pools, particularly effective in early season and during non-hatch periods.

Small Streamers: Woolly Buggers and small baitfish patterns work well in deeper pools and during fall.

Recommended Fly Patterns

Dry Flies: Elk Hair Caddis (#14-16), Parachute Adams (#14-18), Royal Wulff (#12-16), Stimulator (#10-14), Hoppers (#8-12)

Nymphs: Pheasant Tail (#14-18), Hare's Ear (#12-16), Prince Nymph (#12-16), Copper John (#14-18)

Streamers: Woolly Bugger (#8-12), Muddler Minnow (#10-14)

Presentation Tips

Use light tippets (4X-6X) in clear water
Bonneville cutthroat are less wary than other subspecies but still require stealthy approaches in small streams
Focus on pocket water, riffles, and pool edges
Natural drifts are essential in clear water
Early morning and evening fishing is most productive in summer

Best Seasons

Spring (April-June)

Excellent fishing as water temperatures rise. Spawning activity in tributary streams. Good dry fly fishing during mayfly and caddis hatches.

Summer (July-August)

Focus on high-elevation waters and shaded streams. Early morning and evening fishing is best. Terrestrial patterns become effective.

Fall (September-October)

Prime time for Bonneville cutthroat fishing. Aggressive feeding behavior and excellent opportunities with streamers and nymphs.

Winter (November-March)

Limited fishing opportunities due to ice and snow. Some lower elevation streams remain accessible with slow nymph presentations.

Conservation Status

Bonneville cutthroat trout face significant conservation challenges:

Population Status

Listed as a sensitive species in Wyoming. Historic populations have declined dramatically due to habitat loss, hybridization with non-native trout, and competition. Conservation populations are maintained in isolated headwater streams.