Black Hills Fly Fishing Report – August 22, 2025
The Sturgis Rally has wrapped up, and traffic across the Hills has calmed down. With cooler daytime highs, crisp night temperatures, and stable flows, conditions are lining up for some excellent late-August fishing.
Weather Outlook
Friday, Aug 22 – Intervals of sun and clouds with thunderstorms possible. High: 79°F / Low: 56°F.
Saturday–Monday (Aug 23–25) – Pleasant and cooler with highs in the mid-70s to upper 70s and lows in the 50s.
Tuesday (Aug 26) – Mostly sunny and mild. High: 79°F / Low: 56°F.
Late Week (Aug 27–28) – Warming trend returns, with highs back into the mid-80s.
Takeaway: Fish early and late. The cooler nights will help water temps rebound, especially in higher elevation streams. Keep a thermometer handy and give trout a break if temps creep past 67°F.
Streamflow Update
- Rapid Creek at Rapid City – ~50 cfs (slightly down from earlier this week).
- Rapid Creek below Pactola Dam – ~42 cfs, steady.
- Castle Creek – Above Deerfield ~12 cfs Slight bump from recent rains, good for upper-elevation dry-dropper action
- Castle Creek – Below Deerfield ~11 cfs Tailwater remains steady—fishable early and late
- Spearfish Creek at Spearfish ~48 cfs Stable flows; reliable hatch and surface activity
Flows remain below long-term seasonal averages but are stable and very fishable, thanks to recent rains.
Where to Fish Right Now
Castle Creek & Spearfish Creek
Cold, clear, and consistent. Expect BWOs, caddis, and PMDs. Dry flies, dry-dropper rigs, and small streamers are producing steady action, with cloud cover improving surface activity.
Rapid Creek – Below Pactola
Quality over quantity is the name of the game. Look for one or two solid fish using technical dry-dropper or nymph rigs. Focus on soft edges, seams, and structure.
Silver City (Above Pactola)
Stable flows with good early and late activity. Trout are feeding on PMDs and caddis. Foam Caddis, Sparkle Duns, and PMD emergers are top picks. After rain, switch to nymphs or streamers if visibility drops.
Rochford & Upstream
Healthy flows from Rochford to Black Fox Campground. Perfect 3-weight dry-dropper water with plenty of willing trout in pockets and pools.
In-Town Rapid Creek
Trico spinner falls are peaking at first light. Fish are rising in calm pools until about 10 a.m., when water temps climb. Use light tippet (5X–6X), fish early, and always check temps.
Stillwater Report
Sylvan, Legion, Center, Bismarck Lakes – Chironomids, balanced leeches, and small nymphs under indicators in 6–12 feet.
Deerfield & Pactola Reservoirs – Weed edges and drop-offs are producing with leeches and nymph rigs.
Warmwater Update
Bass – Sheridan and Stockade Lakes are hot early and late on topwater. Try Boogle Bugs, MFC Bombshells, and Rio Foam Slice Frogs.
Pike – Pactola is still the place to be. Flashy sink-tip streamers fished in low light cover water efficiently.
Carp – Angostura and Belle Fourche Reservoirs are great for sight-fishing tailers on sandy flats. Hoppers, cicadas, and small terrestrials work well.
Go-To Flies for Late August
Dry Flies
- CDC Thorax Dun (BWO #18–20)
- Sparkle Dun (PMD #16)
- Elk Hair Caddis (#14–16)
- Trico Spinner (#20–22)
- Chubby Chernobyl (#10–18, Tan/Olive/Gold)
- Hippie Stomper (#14–16)
- Hoppers
- Craneflies
Nymphs
- Perdigon (Olive/Purple #16–18)
- Tungsten Zebra Midge (Black/Silver #18–20)
- Split Case PMD or BWO (#16–18)
Dry-Dropper Combos
- Chubby Chernobyl + Perdigon or Zebra Midge
- Short dropper with a PMD/BWO emerger
Final Thoughts
Cooler nights and mild daytime highs will make this a fantastic weekend to fish the Black Hills. Flows are stable, dry-fly activity is strong, and both stillwaters and warmwater options remain excellent backup plans. Keep a thermometer handy, fish mornings and evenings, and switch gears to bass, pike, or carp if streams warm up.
Need hot flies or the latest local intel? Stop by Dakota Angler & Outfitter in Rapid City or check out our online shop at flyfishsd.com
See you on the water,
The Team at Dakota Angler & Outfitter
