Fall Fly Fishing Guide – Denver’s South Platte & Clear Creek

Fall in Denver isn’t just pumpkin spice and football—it’s the best time of year to sneak away for a few casts on the city’s closest rivers. The South Platte and Clear Creek come alive with cooler water, active fish, and fewer crowds once the tubers and summer chaos fade. Here’s your seasonal guide to fishing both streams when the leaves turn gold.

South Platte River in Fall

The Denver South Platte (DSP) stretches about 26 miles through the city. It’s gritty, urban, and absolutely worth fishing when fall rolls around.

South Platte River – Key Fall Sections

Cheesman Canyon

• Why go: Legendary technical water, gin-clear flows, and trophy trout. Fall is prime for sight-fishing spooky rainbows and browns.
• Conditions in fall: Stable flows, cool temps, and brilliant canyon colors. Browns stage for the spawn—be careful around redds.
• Best flies: RS2s (#20–22), Mercury Midges (#20–24), JuJu Baetis (#20–22), small leech and sculpin streamers (#10–12).
• Pro tip: Long leaders (12–14’) with 6X–7X fluoro are essential. Presentation matters more than fly pattern here.

Deckers

• Why go: Perhaps the most popular stretch of the Platte—easily accessible, loaded with fish, and consistent year-round.
• Conditions in fall: Lower crowds than summer, steady flows, and great BWO hatches on cloudy afternoons. Trout are actively feeding.
• Best flies: Blue Wing Olive dries (#18–22), Barr’s Emergers (#20–22), Black Beauty (#20–24), and San Juan Worms after rain events.
• Pro tip: Fish riffle transitions and soft seams in the afternoons—perfect dry-dropper water.

Waterton Canyon

• Why go: Just outside the city, a fantastic blend of accessibility and wilderness feel. Closed to vehicles, but hike or bike in for quality fishing.
• Conditions in fall: Cooler temps, more solitude than Deckers, and plenty of rainbows and browns. Big fish move in from Cheesman and Chatfield during seasonal transitions.
• Best flies: Griffith’s Gnats (#20–22), RS2s (#20–22), caddis emergers, and small streamers stripped tight to boulders.
• Pro tip: Bring a bike—the 6.5-mile canyon road makes reaching upper sections quicker and saves energy for the fishing.

Top fall flies:

• Blue Wing Olive (BWO) Emergers, #18–22
  Cloudy afternoons bring thick BWO hatches. Trout sip emergers just under the surface film—swing these in softer seams.
• RS2, Gray/Olive, #20–22
  A South Platte staple. Dead-drift behind a small attractor or use in a two-fly rig when fish get picky.
• Zebra Midge, Black/Red, #20–24
  Midges dominate in fall and winter. Fish two in tandem under an indicator or Euro-rig style.
• San Juan Worm, Red/Wine, #12–14
  High-protein and effective after fall rains or reservoir releases stir things up.
• Small Streamers (Thin Mint, Mini Bugger, #8–10)
  Especially effective in deeper runs where browns stage pre-spawn.

Pro tip: A long 12–14 foot leader with 5X or 6X tippet makes all the difference on clear fall days. Watch for trout sipping BWOs along softer edges when clouds roll in.

Clear Creek in Fall – Denver’s Quick Mountain Escape

Head west 20–30 minutes and you’re in canyon country. Clear Creek runs from the high country down through Golden, and fall is when it shines.

Why fall rocks here:

• Runoff is long gone, flows stabilize, and water clarity is crystal.
• Browns move into pre-spawn mode—territorial, aggressive, and willing to smack a streamer.
• Golden’s tuber season is over, meaning quieter water access.

Best sections:

• Golden town stretch – easy access, lots of fish, perfect for a quick evening.
• Highway 6 canyon pull-offs – pocket water, riffles, classic fall dry-dropper fishing.
• Above Idaho Springs – cooler temps, fewer anglers, and better cutthroat chances.

Top fall flies:

• Parachute Adams, #18–22
  A perfect match for fall BWOs. Fish afternoons when the canyon shadows cool water temps.
• Elk Hair Caddis, Tan/Olive, #16–18
  Still relevant in September before the first hard freezes. Skitter across riffles for aggressive browns.
• Copper John, Red/Green, #16–18
  Excellent dropper under a small dry in pocket water.
• Pheasant Tail Nymph, #18–20
  A go-to for BWO nymphs; deadly in Clear Creek’s riffle-to-pool transitions.
• Woolly Bugger, Black/Olive, #8–10
  Fall browns are territorial—swing or strip these in deeper pools for violent strike.

Pro tip: Fish afternoons on Clear Creek in fall—water temps are prime after a chilly night, and trout feed heavily mid-day into early evening.

Comparing the Two – Which to Fish This Fall?

• Short on time or fishing after work? Hit the South Platte for trout and carp within city limits.
• Want foliage, mountain air, and feisty browns? Drive 20 minutes west to Clear Creek.
• Streamer junkie? Clear Creek browns in fall will keep you busy.
• Technical nymphing or carp stalker? South Platte delivers urban puzzles and tug-of-war battles.

Fall Fishing Tips for Both Rivers

• Flows matter. Use USGS gauges—look for Platte flows under 300 CFS and Clear Creek in the 100–200 CFS range.
• Match the hatch. BWOs dominate fall afternoons on both rivers. Carry a selection from #18–22.
• Dress in layers. Mornings start frosty, afternoons can still hit 70+.
• Watch the crowds. Early October is golden for fishing without the tubers, but weekends still draw anglers.
• Handle with care. Browns on Clear Creek are heading into the spawn—avoid redds and focus on deeper runs.