Fishing Near Hardin, Montana

Hardin is the gateway to one of the world’s premier trout fisheries. The Bighorn River below Yellowtail Dam—about 45 miles south near Fort Smith—is a world-class tailwater holding brown trout and rainbow trout averaging 14 to 20 inches, drawing fly anglers from around the globe. Add Bighorn Canyon National Recreation Area’s 71-mile-long Bighorn Lake, the Afterbay Reservoir, the Tongue River to the east, and multiple FWP fishing access sites along the Yellowstone River corridor, and Hardin offers a fishing base that punches far above its weight. For Montana's fly fishing heritage, see our Fly Fishing Guide. For the full town profile, see our Hardin guide.

Fishing Access Sites

Montana Fish, Wildlife & Parks maintains public fishing access sites within range of Hardin, primarily along the Yellowstone River corridor. These sites provide boat ramps, shore access, and wade-fishing entry points.

The Bighorn River

The Bighorn River below Yellowtail Dam is Hardin’s headline fishery and one of the most productive trout waters in North America. The tailwater section, centered around the small town of Fort Smith approximately 45 miles south, holds dense populations of brown trout and rainbow trout averaging 14 to 20 inches, with fish over 20 inches caught regularly. Cold, dam-controlled releases maintain stable water temperatures year-round, fueling dense aquatic insect populations that make the Bighorn one of the finest dry-fly rivers in the world.

Most anglers fish the Bighorn from guided drift boats, floating the 13-mile stretch from Afterbay Dam downstream. Guided drift boat trips typically cost $525–$625 per day. Wade fishing is also excellent at multiple access points—the river is wide, relatively flat-bottomed, and wadeable in many areas during normal flows. The Bighorn’s consistency is its greatest asset: unlike freestone rivers that blow out in spring runoff, this tailwater fishes productively 12 months a year.

Peak dry fly fishing arrives in July with prolific hatches of pale morning duns (PMDs), caddis, tricos, and hoppers. Blue-winged olive (Baetis) hatches produce surface feeding in spring and fall, while winter brings excellent streamer fishing and reliable Baetis hatches on overcast afternoons. Nymph rigs with midges, sowbugs, and scuds are productive year-round beneath the surface.

Afterbay Reservoir

Afterbay Reservoir sits 2.2 miles below Yellowtail Dam and covers 181 acres. It holds rainbow trout with a limit of 5 trout combined. The reservoir provides additional fishing opportunity close to the Bighorn River tailwater section and is accessible from the Fort Smith area.

Safety warning: Water levels in Afterbay Reservoir can fluctuate up to 15 feet daily due to dam operations. Anglers should exercise extreme caution, monitor water levels closely, and avoid wading in areas where rapid level changes could create dangerous conditions.

Bighorn Lake

Bighorn Lake stretches 71 miles through Bighorn Canyon National Recreation Area (52 miles from Hardin). The lake offers a different fishery from the tailwater below—walleye, trout, smallmouth bass, and surface-feeding carp are the primary species. Boat access is available at Ok-A-Beh Marina (south end) and at Barry’s Landing and Horseshoe Bend on the north end. The canyon setting is dramatic—sheer walls rising over 1,000 feet above the water—and the lake receives far less fishing pressure than the Bighorn River tailwater.

Rivers Near Hardin

Lakes & Reservoirs

Tongue River & Other Waters

The Tongue River (49 miles east) flows through prairie and ranch country, offering a quieter alternative to the Bighorn. Smallmouth bass, channel catfish, and sauger inhabit the deeper pools and undercut banks. Wade fishing is practical in many stretches during normal flows. The Yellowstone River is also accessible to the north near the Billings area, with multiple FWP access sites along the corridor.

Permits & Regulations

A Montana fishing license is required for anyone 12 and older on all state waters. Licenses are available online at Montana FWP or at local sporting goods stores. Non-resident licenses are available for durations ranging from two days to a full season.

Crow Reservation: The Bighorn River flows through the Crow Indian Reservation. A tribal fishing permit may be required for certain waters on reservation land. Check with the Crow Tribe’s fish and game department for current permit requirements before your trip. State and tribal regulations can differ—verify which jurisdiction applies to the water you plan to fish.

Always check current FWP regulations before fishing any water near Hardin.

Seasonal Guide

Spring (March–May): The Bighorn tailwater fishes year-round, but spring brings increasing insect activity—blue-winged olives and midges produce surface feeding from March onward. The Yellowstone River corridor runs high and muddy with spring runoff from April through mid-June. Lakes begin to open as ice clears in April and May.

Summer (June–August): Prime season across most waters. July is peak dry fly fishing on the Bighorn with PMDs, caddis, tricos, and hoppers all active. Bighorn Lake fishing is productive for walleye and bass. Tongue River smallmouth bass become active as water warms. Hardin’s hot summers push afternoon temperatures into the 90s°F—fish early and late, and the Bighorn’s cold tailwater stays comfortable for trout regardless of air temperature.

Fall (September–November): Many anglers consider fall the best season. Brown trout become aggressive before their October–November spawn, and streamer fishing on the Bighorn produces the year’s largest fish. Blue-winged olive hatches return on overcast autumn afternoons. Fewer anglers on all waters.

Winter (December–February): The Bighorn tailwater is the winter workhorse—stable dam releases keep the water fishable year-round, and midge hatches on warmer winter afternoons bring trout to the surface. Excellent streamer fishing and reliable Baetis hatches make winter on the Bighorn productive fishing rather than an endurance exercise. Dress warmly—January lows near Hardin average in the teens.

For hiking and other outdoor activities near Hardin, see our hiking guide.