Fly Fishing Bear Creek, Idaho: Backcountry Cutthroat Water

A Roadless Creek Above Palisades Dam

Bear Creek drains the Caribou Range in Bonneville County and enters Palisades Reservoir from the southwest. Fish and Game maps it at 22.1 miles and files it as a tributary of the South Fork Snake River. The reservoir sits about 55 miles southeast of Idaho Falls on U.S. 26.

Most of the drainage lies inside the Bear Creek Roadless Area, 118,600 acres split between the old Caribou and Targhee forests. The Forest Service describes parallel ridges from 6,000 to 9,400 feet of grass, brush, aspen, and scattered Douglas fir and lodgepole. Its roadless inventory says the area “has high quality fish habitat and a population of Yellowstone cutthroat trout.”

Roadless does not mean motor-free. The Targhee side has 10 miles of road and 99 miles of trail open to summer motorized travel. When the Forest Service and volunteers replaced the trail bridge over Bear Creek in 2022, the crew of more than 50 rode in by horse, dirt bike, and bicycle.

For more small waters in the state, see our Idaho secret waters guide.

Regulations (Checked September 2026)

Bear Creek is not named in Idaho’s 2025 to 2027 rule book. Fish and Game’s Fishing Planner page for the creek assigns it the “Palisades Reservoir tributaries” special rule, which changes two things from Upper Snake Region general rules.

Do not confuse this with the “South Fork Snake River tributaries” rule for Burns, Palisades, Pine, and Rainey creeks below the dam. Those streams close June 1 to 30 and allow unlimited rainbow harvest. Bear Creek has no June closure.

The rule has tightened over time. Fish and Game’s 2007 cutthroat plan lists Bear, McCoy, and Big Elk creeks under a two-fish limit with nothing under 16 inches. Today the cutthroat limit is zero. The Upper Snake Region office in Idaho Falls answers at (208) 525-7290.

The Fish: Reservoir Cutthroat, Resident Cutthroat, and a Few Browns

Fish and Game’s 2024 survey of Bear Creek recorded brown trout, Yellowstone cutthroat, mountain whitefish, rainbow-cutthroat hybrids, and Utah suckers. Mottled sculpin and speckled dace turned up in 2011, and redside shiners in 2000.

The creek has not been stocked since July 25, 1984, when Fish and Game planted 50,900 Yellowstone cutthroat fingerlings. Three fry plants in 1968, 1969, and 1971 came before that. Nothing has gone in for 42 years.

The trout are doing better than they were. In 1980 a survey crew estimated 18 trout in a 246-meter study reach, all cutthroat. In 2000 the same reach held 72. The 2000 catch was 94 percent cutthroat, 5 percent rainbow or hybrid, and 1 percent brook trout.

The creek’s real engine is the reservoir. Fish and Game’s 2007 plan says the spawning runs into Bear, McCoy, and Big Elk creeks “have recently increased in strength and duration and have become very popular seasonal fishing events.” Those runs include hatchery cutthroat that grew up in the reservoir, and most spawners measure under 16 inches.

Most of the run does not stay long. Fish and Game gave McCoy Creek a July 1 opener because most reservoir fish have returned to the lake by then. Bear Creek has no such closure, but the timing is the same.

Brown trout also reproduce in the reservoir system, and the 2024 survey confirms they use Bear Creek. A long-running Swan Valley angler’s account says a few reservoir browns spawn in the creek in fall but are rarely hooked. Treat a fall brown here as a bonus, not a plan.

Palisades Reservoir: The Lake That Feeds the Creek

Palisades Dam is a zoned earthfill dam 270 feet high and 2,100 feet long, built by the Bureau of Reclamation from 1951 to 1957. Full pool is 5,620 feet and holds 1.2 million acre-feet. The reservoir covers about 15,950 acres with roughly 70 miles of shoreline.

The dam flooded 32 kilometers of what Fish and Game calls historically productive cutthroat habitat and cut off the river fish below. The reservoir can drop 80 vertical feet in a season, which Fish and Game says limits its trout production.

Fish and Game props up the fishery with hatchery cutthroat. In 2025 it stocked 219,483 catchable Yellowstone cutthroat, most of them in a single week of September. Since 2014 the plants go in after irrigation releases slow, so fewer fish wash through the dam. Small numbers of sterile lake trout and 69,190 kokanee fry went in as well.

The 2015 creel survey is sobering. Anglers spent 44,623 hours on the reservoir from May through August and caught 3,814 trout and salmon, a rate of 0.09 fish per hour. Most rated the fishing poor. Netted cutthroat averaged 12.4 inches and browns 16 inches.

The Kokanee Experiment

Bear Creek was Fish and Game’s test stream for building a kokanee run. In August 2015 biologists moved 50 male and 50 female kokanee from Big Elk Creek and released them above a picket weir on Bear Creek. They found redds above the weir and expected fry to emerge around March 1.

The transplants continued through 2019. Fish and Game’s 2025 to 2030 management plan reports that returns “were not observed,” and the Bear Creek effort was suspended. McCoy Creek may get the next trial. The kokanee no-harvest rule stays in force on every Palisades tributary.

Flows and Water Temperature

The USGS gauge on Bear Creek above the reservoir, at 5,640 feet with a 77-square-mile drainage, recorded daily flow from 1917 to 1971. It no longer runs, so there is no live reading. The long record still tells you when to go.

Source: USGS gauge 13032000, Bear Creek above Reservoir near Irwin, monthly means over 24 water years, 1917–1971.

The record peak was 784 cubic feet per second on May 5, 1936. The smallest annual peak was 60 in the 1934 drought. The creek is a spring torrent in May, drops fast through June, and settles into wadeable pocket water by mid-July.

The gauge also logged water temperature from 1977 to 1979. Daily highs reached 72 degrees in July and topped 70 in June and August. That is warm for cutthroat. In midsummer, fish the morning, land fish quickly, and keep them in the water.

Getting There

The Bureau of Reclamation no longer lets the public drive across the dam, so the Calamity side is a five-mile washboard detour. Fish and Game notes that the reservoir’s boat ramps are crowded all summer.

The Caribou-Targhee’s grizzly food storage order covers the Teton Basin, Ashton/Island Park, and Dubois districts, not Palisades. This is still bear country with elk and deer winter range all around you. Store food well and carry spray.

How to Fish It

Walk in. Angler reports agree that the fishing improves a half hour or more above the trailhead lot, where the creek meanders through meadow with beaver ponds and open backcasts. A 3- or 4-weight rod and a floating line cover it.

From July on, an attractor dry in size 12 to 14 will bring cutthroat up, and hoppers, ants, and beetles take over as the grass dries. Work the pool tailouts and the seams along beaver dams, where the larger resident fish hold. Expect mostly 6- to 10-inch cutthroat, with the odd fish to 14 or 16 inches.

Every cutthroat goes back, by rule. Wet your hands, skip the net if you can, and keep the fish in the water for the photo. If you want to work the deeper runs early in the season, our nymph fishing guide covers the rigging.

For a longer eastern Idaho trip, pair this creek with Moose Creek and Sheridan Creek in the Island Park country to the north.

Frequently Asked Questions

Where is Bear Creek in Idaho?

Bear Creek is a 22-mile tributary of the South Fork Snake River in Bonneville County. It enters Palisades Reservoir from the southwest, about 55 miles southeast of Idaho Falls, inside the 118,600-acre Bear Creek Roadless Area. You reach the trailhead on Bear Creek Road, a gravel forest road that leaves Snake River Road below Palisades Dam.

What are the fishing rules on Bear Creek?

Fish and Game’s planner assigns Bear Creek the Palisades Reservoir tributaries rule: open all year, trout limit six, but no harvest of cutthroat trout or kokanee. Brook trout have a separate limit of 25. There is no bait ban, no barbless rule, and no June closure. You may not fish inside the posted boundary of a fish weir or trap.

When is the best time to fish Bear Creek?

Late June through September. The USGS gauge near the mouth averaged 311 cubic feet per second in May, 189 in June, 86 in July, and 47 in August. Reservoir cutthroat run up the creek in spring and are mostly back in the lake by July 1. Water hit 72 degrees in July, so fish early and release fast.

What fish live in Bear Creek?

Fish and Game’s 2024 survey found brown trout, Yellowstone cutthroat trout, mountain whitefish, rainbow-cutthroat hybrids, and Utah suckers. The creek was last stocked in 1984. A 2000 survey put the trout population at 94 percent cutthroat, 5 percent rainbow or hybrid, and 1 percent brook trout.

Sources and Check Dates

• Idaho Department of Fish and Game, Fishing Seasons and Rules 2025–2027, second edition 2026, Upper Snake Region pages 41–44. Checked September 2026.
• IDFG Fishing Planner, Bear Creek (species surveys, stocking records, rules block) and Palisades Reservoir. Checked September 2026.
• IDFG, Management Plan for Conservation of Yellowstone Cutthroat Trout in Idaho, April 2007, Palisades/Salt River unit and Tables 7 and 8.
• IDFG, Fisheries Management Plan 2025–2030, South Fork Snake River and Palisades Reservoir chapter.
• IDFG, Palisades Reservoir 2015 annual report abstract (High and Garren): creel, gillnet, and kokanee transplant.
• USGS gauge 13032000, Bear Creek above Reservoir near Irwin: monthly statistics 1917–1971, peak flows, water temperature 1977–1979. Checked September 2026.
• Bureau of Reclamation, Palisades Project and Palisades Dam pages. Checked September 2026.
• USDA Forest Service, Caribou-Targhee National Forest: Palisades Ranger District, Palisades Reservoir, and Calamity Campground pages; Food Storage Order 04-15-23-217; press release on the Bear Creek bridge (May 2022). Checked September 2026.
• USDA Forest Service, Idaho Roadless Areas FEIS Appendix C, Bear Creek #615.
• Angler reports on access and fly choice: anglerguide.com (Swan Valley’s Bear Creek) and a July 2014 trip report at wellerfish.me, used only where noted.