Beaverkill-Willowemoc Fishing Report: August 31, 2026

Quick Summary

The Beaverkill-Willowemoc system is fishable this morning, but the freestones are still a measured late-summer call. USGS showed the Beaver Kill at Cooks Falls at 260 cfs, 1.92 feet, and 61.5 F, while Willowemoc Creek near Livingston Manor was 48.5 cfs, 1.97 feet, and 59.4 F during the 9 AM refresh. Both rivers are lower than yesterday morning, so wading is more approachable, but lower water and a forecast high near 73 F mean the afternoon should be governed by a thermometer and the storm line. Fish early, use the clouds, stay close to shade and oxygenated riffles, and remember that the Beaverkill Horton Brook thermal-refuge closure remains in effect through August 31.

Conditions Snapshot

Field	Value
Status	Fair. Morning temperatures and cloudy weather are workable, but falling freestone flows and afternoon warming keep the trout window selective
Flow	260 cfs at Beaver Kill at Cooks Falls; 48.5 cfs on Willowemoc Creek near Livingston Manor
Gauge Height	1.92 feet at Cooks Falls; 1.97 feet at Livingston Manor
Water Temp	61.5 F at Cooks Falls; 59.4 F on Willowemoc Creek near Livingston Manor
Clarity	Not reported by official gauges; recent regional context has area rivers dropping after late-week rain
Trend	Falling compared with yesterday morning on both gauges
Best Window	Morning, cloudy periods before storms, and evening only if lightning is gone and water temperatures remain safely below 68 F
Best Method	Small dries, terrestrials, wet flies, and light nymphs in edges, riffle margins, pocket water, and shaded runs
Wadeability	Limited to fair. Easier than recent higher water, but avoid slick ledges, pushy slots, and unnecessary crossings

Weather

For Roscoe, the National Weather Service 9 AM update calls for a high near 73 F, light south wind, and showers and thunderstorms through the afternoon, with precipitation chances rising quickly after early afternoon. The hourly forecast shows patchy fog at 9 AM, isolated showers late in the morning, then showers and thunderstorms by midafternoon; tonight also keeps showers and thunderstorms likely. Cloud cover should help trout feel less exposed, but lightning and a quick shower-driven change in color are the practical checks before staying late.

River Notes

The Beaver Kill and Willowemoc are both lower than yesterday morning. That gives anglers more edges and pockets to fish from shore, but it also means trout have less cover and can become easier to spook. The morning water temperatures are safe; the afternoon is not automatic. Carry a thermometer and stop targeting trout if readings approach 68 F.

Official gauges do not report clarity. With the system dropping, expect improving conditions where yesterday's rain stain has cleared, but inspect each reach before committing to tiny dries. In clear water, lead with terrestrials, olives, Isonychias, Cahills or Summer Stenos, and tan caddis. If you find a touch of stain or broken water, a soft hackle, small nymph, or brief streamer pass can cover pockets without overplaying warm-water trout.

Hatch Activity

Official gauges do not report hatches. Current Catskills source context from the 9 AM refresh supports strengthening Blue Winged Olives, flying ants, Hebes, White Flies, Isonychias, Light Cahills, 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	Most useful in clouds, shade, riffle edges, and soft pockets
Flying Ant or Beetle	16-24	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	12-24	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	Only worth a short test if stain remains or showers add cover

Tactics

Start from the bank and fish the near water first. On the Beaver Kill, cover shaded riffle shoulders, cushions behind rocks, and soft inside edges. On the Willowemoc, a terrestrial, small olive, or soft hackle can move fish in pockets without adding much weight. Keep the trout fight short, wet your hands, carry a thermometer, and do not fish the Horton Brook thermal-refuge reach until the seasonal protection ends.

Gauge Links

Gauge	Flow	Temp	Link
BEAVER KILL AT COOKS FALLS NY	260 cfs	61.5 F	USGS 01420500
WILLOWEMOC CREEK NR LIVINGSTON MANOR NY	48.5 cfs	59.4 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.