Black Hills Fly Fishing Report – September 13, 2025
We’ve had a run of warmer weather this past week, and it definitely showed in some of the streamflows and water temperatures. The good news? A cool-down is rolling in starting Sunday, and that should really help settle things back into prime trout-fishing shape. Cooler, cloudy days in the forecast also mean one thing: Blue Winged Olives are about to shine. Expect those little mayflies to become more and more important over the next couple of weeks.
In the meantime, terrestrial fishing is still rocking—hoppers, ants, and beetles are all producing solid eats. Keep a few foam bugs handy, because fish are still looking up.
Streamflow Check
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Castle Creek (Above Deerfield): ~14 cfs – good pocket-water flows, perfect for a dry-dropper setup.
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Castle Creek (Below Deerfield): ~11 cfs – low and technical, so think light tippet and stealth mode.
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Spearfish Creek at Spearfish: ~48 cfs – consistent as ever, one of the most reliable bets right now.
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Rapid Creek (In-Town): Still some Trico action early, but water temps have been touchy in the afternoons. Mornings are your best bet, or head upstream if things start to creep up.
What’s Working
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Dries:
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CDC Thorax Dun (BWO, #18–20) – going to be more and more important.
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Elk Hair Caddis (#14–16) – still plenty of caddis around.
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Chubby Chernobyls & Hippie Stompers (#10–16) – doubles as a terrestrial and dry-dropper rig anchor.
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Trico Spinners (#20–22) – early AM option on Rapid.
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Nymphs:
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Perdigons (#16–18, olive/purple)
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Zebra Midges (#18–20, black/silver)
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Small BWO/PMD emergers (#16–18)
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Terrestrials:
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Hoppers (#8–12, tan/green/pink)
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Ants & Beetles (#14–16)
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Lakes & Warmwater
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Sylvan, Center, Bismarck, Legion Lakes: Balanced leeches, chironomids, and nymph rigs in 6–12 feet.
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Pactola & Deerfield Reservoirs: Slow-stripped leeches off drop-offs and weed edges are still solid.
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Sheridan & Stockade (Bass): Topwater early and late is still a blast.
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Carp at Angostura/Belle Fourche: Great sight-fishing opportunities—don’t leave the hopper box at home.
Quick Take
The warm spell slowed things a bit last week, but this next stretch of cooler, cloudier weather should really open up the fishing again. Blue Winged Olives are about to become the main event, and terrestrials are still producing in a big way. If you’re planning a day out, Sunday and early next week look excellent.
Swing by the shop if you need updated bug picks or just want to talk strategy—we’ve got plenty of ideas to get you on fish.