Youngs Creek and Danaher to Big Prairie
The South Fork is born deep in the Bob Marshall Wilderness where Youngs Creek and Danaher Creek meet, and it flows north for more than 40 wilderness miles before it reaches a road. The upper river is open, meandering meadow water with logjams and big views, reached by multi-day trips over the passes from trailheads on every side of the wilderness, including Benchmark and Holland Lake. Nobody floats a raft in here without packing it on a horse or on their back.
Salmon Forks to Meadow Creek
Below Big Salmon Creek the valley narrows and the river runs between timbered walls to Meadow Creek Gorge, a narrow slot with drops that stops all but expert kayakers. Floaters take out at a marked point above the gorge and walk about three miles to the Meadow Creek trailhead. Meadow Creek pack bridge, the trailhead at the end of the road, is the easiest way in, and the fishing improves with every mile you walk upstream from it.
Spotted Bear to Hungry Horse Reservoir
From Meadow Creek the river runs another 18 miles past Spotted Bear Ranger Station to the head of Hungry Horse Reservoir, with road access from the long gravel reservoir road that starts at Hungry Horse Dam, roughly 50 miles of driving. This page's gauge sits below the Spotted Bear River near Twin Creek. Below the dam itself the South Fork runs only five miles to the main Flathead, a cold tailwater that is a different, minor fishery.
Westslope cutthroat
The South Fork holds Montana's largest genetically pure population of native westslope cutthroat, plus mountain whitefish. Many of the cutthroat migrate up out of Hungry Horse Reservoir, and Montana Angler describes them as mostly 12 to 18 inches with a few over 20. They eat dry flies all summer once the water drops: stoneflies and caddis in July, then hoppers and attractors into September.
Bull trout
The South Fork drainage is the largest bull trout stronghold in the lower 48 and one of the few places in Montana where you can legally target them, but only from July 1 through July 31, catch and release, with a Hungry Horse/South Fork Flathead bull trout catch card in your possession. Fishing for them in tributaries is never allowed, and all bull trout must be released without delay.
Season and regulations
Runoff keeps the South Fork high until around the first week of July in a normal year. Bedrock and Paradox's flow guide, keyed to the Twin Creek gauge, says packrafts float the river from the low 400s up to about 5,000 cfs, that the upper meadows get draggy below 1,200 cfs and the lower river gets pushy above 5,000. Wade fishing is the norm and is comfortable once the river drops toward its summer base, so this page treats 500 to 2,000 cfs as in range.
The wilderness river from Youngs and Danaher creeks to Crossover boat ramp follows the Western District season, the third Saturday in May through November 30, with single-point hooks only. Cutthroat: 3 daily, none over 12 inches, except catch and release from Meadow Creek bridge to the Spotted Bear footbridge. The mouths of Gordon and Little Salmon creeks are closed from June 15 to September 30. A Montana license is required. Confirm in the current Montana FWP regulations.