What to expect at Butterfly Lake

Butterfly Lake sits at roughly 10,000 feet in the Uinta Mountains east of Kamas, a high-country destination that holds cutthroat and brook trout in cold, clear water. The lake is small — maybe 10 acres — and shallow enough that fish are visible from shore on clear days. Access is a moderate hike of about 4 miles one way from the Mirror Lake Highway trailhead, gaining elevation steadily but not steeply. The water stays cold year-round, which keeps the trout active even in mid-summer when lower-elevation reservoirs warm up.

The lake sits in a cirque basin with rocky shores and sparse alpine vegetation. Afternoon wind is common at this elevation, and weather can change fast — afternoon thunderstorms are typical in July and August. The season runs roughly from July through September; snow blocks access before and after. Because the hike is moderate and the scenery is open, Butterfly Lake draws both anglers and day hikers, especially on weekends.

Key Takeaways

  • Butterfly Lake holds native cutthroat trout and introduced brook trout, both responding well to small flies and spinners in the 8- to 12-inch range.
  • The hike from Mirror Lake Highway is 4 miles one way with steady elevation gain; start early to avoid afternoon thunderstorms and crowds.
  • A Utah fishing license is required; the lake sits in the Daggett County drainage and follows standard statewide regulations with no special restrictions.
  • Water temperature stays in the 50s even in summer, so fish feed throughout the day rather than shutting down at midday like warm-water species.
  • Camping is available at Mirror Lake and nearby sites along the highway, making this a two-day trip rather than a day hike for most anglers.

Getting to the trailhead and hiking in

From Kamas, take US-150 (Mirror Lake Highway) east toward the Uinta Mountains. The road climbs steadily and passes several campgrounds and smaller lakes. The trailhead for Butterfly Lake is marked and sits along the highway; parking is available in a small lot. The hike itself follows a well-maintained trail that gains roughly 1,500 feet over 4 miles, passing through subalpine forest and then opening into alpine meadow as you approach the lake.

The trail is rocky in places and can be muddy after rain, so boots with good ankle support are worth the weight. Water sources are available along the trail, but carrying a filter or purification tablets is safer than relying on streams. The hike takes most people 90 minutes to 2 hours going up; descent is faster. Start before 8 a.m. if you want to fish for several hours before afternoon weather moves in.

What fish live here and how they feed

Butterfly Lake holds both native cutthroat trout and brook trout that were stocked years ago. The cutthroat are the original species and tend to be more aggressive and less selective than brook trout in other settings, though at this elevation both species are active feeders. Fish in the lake run mostly 8 to 12 inches, with occasional larger fish in the 14- to 16-inch range. The population is healthy but not dense, so you will not see constant rises or have fish hitting every cast.

At 10,000 feet, water temperature stays in the 50s even in July and August, which means trout feed throughout the day rather than shutting down at midday. Midges and small mayflies are the primary natural food, so flies in sizes 16 to 20 work well. Cutthroat in particular respond to small spinners and spoons, especially in silver or gold. The lake is shallow enough that you can reach most productive water from shore, though a float tube or small raft would extend your range if you pack one in.

Fly and spin-fishing tactics

For fly fishing, bring a 4- or 5-weight rod and both floating and sinking lines. Small nymphs — pheasant tail, hare's ear, and midge pupae in sizes 16 to 20 — work throughout the day. Dry flies like Adams, pale morning duns, and small caddis patterns produce during the brief evening rise, usually between 6 and 8 p.m. Cast near the rocky shoreline and along any visible drop-offs; the lake is so shallow that fish are rarely more than 15 feet from shore.

Spin anglers should bring small spinners (sizes 0 to 1) in silver, gold, or copper, and small spoons like Kastmasters or Krocodiles. Cast toward structure — rocks, submerged logs, any visible change in bottom color — and retrieve slowly. The fish are not aggressive enough to chase fast-moving lures, so a steady, deliberate retrieve works better than erratic twitching. Early morning and evening produce more consistent results than midday, though the cold water means fishing is never completely dead.

Regulations and licensing

You need a valid Utah fishing license to fish Butterfly Lake. Licenses are available online through the Utah Division of Wildlife Resources website, at sporting goods stores in Kamas and surrounding towns, or at the Mirror Lake visitor center if it is staffed. A one-day license costs less than a full-season license if you are visiting for only a few days.

Butterfly Lake follows standard Utah statewide regulations: no special restrictions, no slot limits, and standard daily catch limits. Check the current Utah fishing guidebook before you go, as regulations can change year to year. The lake sits in the Daggett County drainage and is open to year-round fishing in theory, but snow and access make it practical only from July through September.

When to fish and what weather brings

July and August are the primary fishing months, with September still viable but with shorter days and colder nights. July tends to be warmer and more crowded; August brings more afternoon thunderstorms but fewer hikers. Early morning is best for both fly and spin fishing — fish are more active and the weather is more stable. By 2 p.m., afternoon wind picks up and thunderstorms become likely, especially in August.

Afternoon thunderstorms at 10,000 feet are not something to ignore. Lightning strikes are a real risk, and the storms move in fast. If you see clouds building to the west or hear thunder, head back down the trail immediately. The hike down is faster than the hike up, and you can always return another day. Bring rain gear even if the forecast looks clear; weather at this elevation changes without warning.

Camping and multi-day trips

Mirror Lake Campground sits along the highway about 10 miles from the Butterfly Lake trailhead and offers developed sites with water and vault toilets. Several smaller campgrounds line the highway as well. If you want to fish Butterfly Lake and explore other nearby lakes — Kidney Lake, Notch Lake, and others are accessible from the same general area — a two-day trip makes sense. This also lets you fish evening and morning without the pressure of a single-day hike.

Backcountry camping is allowed in the Uinta Mountains, but check current regulations with the Forest Service before you go. Water is abundant at this elevation, and the alpine environment recovers slowly from impact, so camp on durable surfaces and pack out everything you pack in. The Mirror Lake Highway corridor is popular, so established campsites are preferable to creating new ones.

Frequently Asked Questions

Do I need a float tube or can I fish from shore?

You can fish effectively from shore — the lake is shallow and small enough that most productive water is within casting range. A float tube or small raft extends your range and lets you reach deeper pockets, but it is not necessary. If you pack one in, the extra weight is worth it only if you plan to spend a full day fishing.

What is the best time of day to fish?

Early morning, from first light until 10 a.m., is most consistent. Evening between 6 and 8 p.m. produces a brief rise, especially for dry flies. Midday fishing is slower but still possible because the water is so cold. Avoid the 2 to 5 p.m. window when afternoon wind and thunderstorms are most likely.

Can I make this a day trip from Kamas?

Yes, but it is a long day. The drive is about 45 minutes, the hike up is 90 minutes to 2 hours, and you have maybe 3 to 4 hours of fishing before you need to head back down. A two-day trip with camping lets you fish more comfortably and explore other nearby lakes.

What if the trail is still snowy in early July?

Call the Mirror Lake Ranger District or check their website for current conditions. Snow can linger into July at this elevation, and a snowy trail is harder to follow and slower to hike. If the trail is mostly clear, you can still make it; if it is mostly snow, wait a week or two.

Are there fish in Butterfly Lake year-round?

Yes, but the lake is under ice from October through June, and the hike is not practical in winter. The fishing season is effectively July through September when the trail is snow-free and the weather is stable enough to be safe.