Beaverkill-Willowemoc Fishing Report: September 2, 2026

Quick Summary

The Beaverkill-Willowemoc system is fishable this morning, but it is a late-summer freestone report with a narrow safety margin. USGS showed the Beaver Kill at Cooks Falls at 409 cfs, 2.42 feet, and 64.0 F during the 8 AM check, while Willowemoc Creek near Livingston Manor was 77.9 cfs, 2.15 feet, and 62.1 F. Recent Catskills source context still supports nymphs, wet flies, small emergers, cripples, spinners, olives, terrestrials, Isonychias, Cahills, caddis, Tricos, and late sulphurs. Fish the morning and cloudy windows, carry a thermometer, and leave the water for lightning or if trout water approaches 68 F.

Conditions Snapshot

Field	Value
Status	Fair. Morning water temperatures and workable flow create opportunity, but freestone warming, thunderstorms, and selective late-summer trout keep expectations moderate
Flow	409 cfs at Beaver Kill at Cooks Falls; 77.9 cfs on Willowemoc Creek near Livingston Manor
Gauge Height	2.42 feet at Cooks Falls; 2.15 feet at Livingston Manor
Water Temp	64.0 F at Cooks Falls; 62.1 F on Willowemoc Creek near Livingston Manor
Clarity	Not reported by official gauges; inspect each reach after recent and forecast storms before committing to small dries
Trend	Mixed but generally stable compared with yesterday morning: Beaver Kill is up slightly, Willowemoc is down slightly
Best Window	Morning into early afternoon cloud cover, then evening only if lightning is gone and water temperatures remain below 68 F
Best Method	Small dries, terrestrials, wet flies, and light nymphs in edges, riffle margins, pocket water, and shaded runs
Wadeability	Limited. Flows are fishable, but wet ledges, pushy slots, and thunderstorm runoff argue for conservative crossings

Weather

For Roscoe, the National Weather Service forecast calls for a high near 70 F, mostly cloudy skies, southeast wind around 6 mph, and showers or thunderstorms developing from midday into afternoon. Tonight is the larger hydrology concern, with showers and thunderstorms likely to produce 1 to 2 inches of rain. Cloud cover helps the trout window today, but lightning and quick stain are practical stop signs.

River Notes

The Beaver Kill has a little more water than yesterday morning, while the Willowemoc is slightly lower. Both are in fishable ranges at the morning check, and the added broken water on the Beaver Kill should help fish hold in riffle shoulders, pocket seams, and bank cushions. Morning temperatures are still under the 68 F trout-stress threshold, but the Beaver Kill is close enough that afternoon fishing should be thermometer-led rather than schedule-led.

Official gauges do not report clarity. If either river carries stain from local cells, start with soft hackles, small nymphs, or a short streamer pass in pocket water and softer edges. If clarity is good, fish from the bank first with ants, beetles, small olives, Isonychias, Cahills, caddis, or Tricos before stepping into the near lane. Keep fish wet, shorten fights, and avoid warm refuge water even though the prior Horton Brook thermal-refuge closure window has ended.

Hatch Activity

Official gauges do not report hatches. Recent Catskills source context supports Blue Winged Olives, flying ants and beetles, Isonychias, Light Cahills or Summer Stenos, tan caddis, Tricos, and a few fading sulphurs, with the best freestone work still weighted toward mornings, clouds, and safe evening temperatures.

Hatch	Size	Notes
Blue Winged Olive	18-24	Useful in clouds, shade, riffle edges, and soft pockets
Flying Ant, Beetle, or Small Hopper	10-24	Work banks, grass edges, foam seams, and quiet pockets before wading through them
Isonychia	10-14	Fish dries, wets, or swimming nymphs along riffle margins and pocket seams
Light Cahill or Summer Steno	14-16	Useful as a searching dry and for mixed evening rise forms if temperatures allow
Tan Caddis	16-20	Fish pupa or soft hackles through riffles when no steady rises show
Trico	20-24	Possible in calmer morning slicks; use only where water stays cool and fish are feeding steadily
Sulphur	16-20	Late and sporadic, but still worth carrying for cooler windows

Recommended Flies

Category	Fly	Size	Notes
Dry	BWO Comparadun, CDC Olive, or Parachute Adams	18-24	Cover small olives in shaded seams, riffles, and softer pockets
Dry	Flying Ant, foam ant, beetle, or small hopper	10-24	Fish banks, grass edges, and foam seams with a patient drift
Dry	Isonychia Parachute, Light Cahill, Summer Steno, or Sulphur	10-20	Search broken water and be ready for evening surface work if temperatures are safe
Dry	Trico spinner	20-24	Use for calm morning feeders where the water remains cool
Wet	Soft Hackle Pheasant Tail, Partridge and Orange, or Isonychia Wet	12-18	Swing through pocket seams and riffle tails before or between rises
Nymph	Pheasant Tail, Frenchie, Hare's Ear, caddis pupa, or Isonychia Nymph	12-20	Use modest weight and target edges, plunge pockets, and oxygenated riffles
Streamer	Small Woolly Bugger or sculpin	6-10	Worth a short test if rain stain develops or showers add cover

Tactics

Start close. Fish the bank water, soft inside seams, and pocket margins before stepping into the river. On the Beaver Kill, use the stronger flow to cover riffle shoulders and cushions behind larger rocks. On the Willowemoc, a terrestrial, small olive, or soft hackle can move fish in pockets without much weight. Take a temperature reading before any afternoon trout fishing, keep fights short, and leave the water when thunder is near.

Gauge Links

Gauge	Flow	Temp	Link
BEAVER KILL AT COOKS FALLS NY	409 cfs	64.0 F	USGS 01420500
WILLOWEMOC CREEK NR LIVINGSTON MANOR NY	77.9 cfs	62.1 F	USGS 01419500

Sources

Official sources checked: USGS stations 01420500 and 01419500, plus the National Weather Service forecast for the Roscoe, NY area. This report is an original Custom FlyBox summary based on current official gauge and weather data, with local public conditions reports reviewed separately for hatch, method, clarity, and safety context.