Tailwater · Sandstone Shale · New York

Upper Main Stem Delaware River

Upper Main Stem Delaware River terrain map

The big water — wide, wild and full of leaping river-bred rainbows, buffered cold where the two branch releases meet at Hancock and warming as it runs down through the border country.

Marginal · Rainbow Trout
Trico Spinner · 20-24
Marginallive now
Slow going — pick your moments
River high but settled. Slow going — pick your moments and do not force it.
90% confidence
What moved it
  • Level1.87 mLast reading 11h ago
  • Water temp18.5°C
  • ClarityClear
Today's fly
TS
Trico Spinner20-24
Proven pattern for this period
Conditions on the water
Live gauge
Level
Steady
1.87 m
Last reading 11h ago
Water temp18.5°C
ClarityClear
Weather21°C
WindSW 15 km/h
Pressure1012 hPa
Rain · recent0.0 mm
Rain · ahead0.1 mm

Live readings only. Trends shown where the gauge supports them.

Water temperature for Rainbow Trout
Warm — slow
18.5°Cideal 10–18°C
0°14°28°
How to fish it · for Rainbow Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Water at 18.5°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6am

Hatch predictions

Today's headline hatch shown — see all 3 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
SulphurHatch
2
3
2
Trico (Eastern)Hatch
2
3
3
2
Eastern Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Eastern Summer BWO (Drunella)Hatch
2
3
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Rainbow Trout fly box
Local fly shops: Dette Flies·Beaverkill Angler
Beats · 3 · 1 reaches

The main stem is big NY/PA border water below Hancock — a New York or Pennsylvania license is valid, with the Delaware border-water trout regulation (April 1–Oct 15, one trout daily; Oct 16–Mar 31 catch-and-release, artificial lures only). It runs through the Upper Delaware Scenic and Recreational River corridor, with NPS and NY/PA public access points, but much of the frontage is private and the river has deceptively fast water, steep drop-offs and cold-water hazards — this is mostly a drift-boat river. The hard truth in summer is temperature: the main stem can be too warm for trout even when the flow looks perfect, so the cold branch releases at Hancock are the refuge, and the lower reaches become a smallmouth fishery in the heat. Confirm current NY DEC / PA FBC regulations before you go.

Main Stem · 3 beatsDay rods
Hancock to Lordville, Lordville to Callicoon, Callicoon to Narrowsburg
The 3 beats
Hancock to LordvillePublic
NY/PA border water — NPS corridor, NY DEC / PA FBC
The upper main stem just below the Hancock junction — buffered cold by the two branch releases and the strongest wild-trout reach of the big water, excellent in the right thermal window. A drift-boat river with NPS and public access points; the bank is largely private.
Border water — NY or PA license valid; Delaware border-water trout regulation applies. Strong water-temperature override: trout fishing collapses as it warms, and fish stack at the cold branch confluences — fish the refuge, don't crowd it. Fast, hazardous big water; public water does not mean public bank.
Lordville to CallicoonPublic
NY/PA border water — NPS corridor, NY DEC / PA FBC
Big-water trout in the wild-trout-to-smallmouth transition — excellent in spring and the cool shoulders, but the summer heat risk climbs as you go downstream. A drift-boat reach through the scenic corridor with public access points and mostly private frontage.
Border water with the Delaware trout regulation. Thermal risk rises downstream — trout fishing becomes a temperature question and the reach turns toward smallmouth in the heat. Fast big water; public water, private bank between access points.
Callicoon to NarrowsburgPublic
NY/PA border water — NPS corridor, NY DEC / PA FBC
The warmer lower reach of the upper Delaware — primarily a smallmouth-bass fishery through much of the season, with trout only a realistic target when the water stays cool. Public boat ramps and access through the scenic corridor; treat trout here as conditional, not the headline.
Border water; the Delaware trout regulation still applies, but this reach warms enough that it's smallmouth-dominated in summer — surfaced as informational for trout, not a trout recommendation in the heat. Fast big water with cold-water and current hazards; public water, private bank between access points.
Permits & access
Permit required — see local rules.
  • NY/PA border tailwater-fed main stem
What's coming
Plan ahead
5-day outlook
Water here at 18.5°C. Nothing cooler within range.
About this water

The big water — wide, wild and full of leaping river-bred rainbows, buffered cold where the two branch releases meet at Hancock and warming as it runs down through the border country. In high summer the whole game is finding the cold water: the main stem is the textbook case for chasing thermal refuge, and knowing where the nearest cooler water is can make or break the day.

  • Sandstone shale
Water quality · US Clean Water Act
  • Aquatic life: Not assessed
  • Fish consumption: Impaired
What this classification means

Fish consumption: Consumption advisory (Mercury) — fish for sport, not the table.

EPA ATTAINS assessment unit 'Delaware River-25868582' (PA-SCR-25868582), 2024 Integrated Report. Aquatic Life use: not assessed. Listed impairment causes: Mercury. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · PA-SCR-25868582

The full read · show the working · for Rainbow Trout · confidence 90%
How the 37 is built — score × weight = contribution
Temperature84 × 28%23.5
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time65 × 13%8.5
Pressure75 × 7%5.3
Insect activity68 × 12%8.2
Conditions total= 78
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts