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Should I go fishing?
Go with caution.
Best option: Wading. Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
Check first: Water temperature is unconfirmed. Use a stream thermometer before fishing.
Fishing rating68
Rating updatedRiver local time:
Why this recommendation?
A Flood Watch is active near this forecast point, so the score is capped until runoff, clarity, crossings, and road access are checked. NWS alert: Flood Watch issued September 12 at 2:21AM EDT until September 13 at 12:00PM EDT by NWS Mount Holly NJ.
Available live dataHighHow much of the live flow, weather, and alert data came back.
Confidence in this recommendationMediumWater temperature not verified; do not use this score to clear warm-water risk.
Usually checks again about every 45 minutes
If you go
- Check first
- Use RiverReports or USGS at High Bridge before wading the gorge or nearby reaches.
- Try
- Confirm the Ken Lockwood Gorge rule set before fishing the gorge.
- Leave when
- Skip the South Branch when Ken Lockwood Gorge rules are unclear, when flow makes the gorge unsafe, when warm weather pushes trout toward stress, or when obvious access is already crowded enough to flatten the experience.
Flow and weather
Showing server-checked river conditions while current readings refresh.
- Flow
- 49 cfs
- From the latest stored river check. Open the official source for the newest reading.
- Air forecast
- 58°F
- Next 24h high
- 78.0°F
NWS air forecast near
- Rain chance
- 0%
This is an air forecast, not a river-temperature reading. Check the water with a stream thermometer before fishing in hot weather.
Latest stored weather check
Mostly Clear
- Wind
- 5 mph
- Weather checked
More forecast and source details
Mostly Clear
National Weather Service
South Branch Raritan near High Bridge
The National Weather Service forecast is temporarily unavailable.
Live data
Where these readings come from
RiverReports gauge: South Branch Raritan River near High Bridge
Flies for this time of year
Seasonal starting points, not a live hatch report. Match what you see on the water.
- Ant PatternsFoam antView fly guide ↗
- Beetle PatternsbeetleView fly guide ↗
- Grasshopper Patternssmall hopperView fly guide ↗
- Blue-Winged Olive PatternsBWOView fly guide ↗
- Zebra MidgeView fly guide ↗
See flies for every season
SeasonWhat to look forFlies to try
March to April
What to look forMidges, early stones, BWOs, stocked-trout nymphing
May to June
What to look forCaddis, sulphurs, March Browns, crane flies, light mayflies
July to SeptemberThis season
What to look forTerrestrials, tricos in slower water, ants, beetles, summer caddis
Flies to try
Also try trico spinner, dry-dropper
Fall and winterThis season
What to look forBWOs, midges, scuds, small streamers during legal trout windows
Flies to try
Each fly name opens its matching Fly Box guide.
More fishing tips
Methods, fish species and trip notes
How to fish South Branch Raritan River today.
Best windows are cool, moderate flows with clear water and legal access. High water makes the gorge dangerous, and low clear water rewards small flies, longer leaders, and patient presentations.
Moderate and clear
Fish small nymphs, caddis, BWOs, and careful dry-dropper rigs.
Low clear water
Use long leaders, 6X, smaller flies, and stealth.
Slight stain
Try small streamers or larger nymphs near banks and plunge pools.
High water
Avoid gorge wading. Fish elsewhere or wait for a safer drop.
Wading, bank fishing or floating?
Best access methodWading
These scores compare the risks of wading, bank fishing, and floating.
Wading · Best fit68/100
Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
Bank fishingNot recommended
This report does not recommend bank fishing on this reach.
FloatingNot recommended
This report does not recommend floating this reach.
Full river report
Is South Branch Raritan River worth the trip today? Check flow, weather, hatches, access, and rules for New Jersey before you go.
The South Branch Raritan is one of New Jersey's best-known trout rivers. Ken Lockwood Gorge is the headline reach, but the broader river has multiple access points and rule sets that need current checks.
Fishing words used on this page
- U.S. Geological Survey (USGS) gauge
- A USGS gauge is an official river station that measures flow or water height.
- Cubic feet per second (cfs)
- Cubic feet per second, or cfs, shows how much water passes the gauge each second.
- Technical fishing
- Technical fishing means the fish are hard to fool, so careful casts and natural drifts matter.
- Nymph
- A nymph is a young water insect. Anglers also use the word for a fly that copies it.
- Presentation
- Presentation means how you cast and move the fly so it looks natural to a fish.
- Seam
- A seam is the line where fast and slow water meet.
- Blue-winged olive (BWO)
- Blue-winged olives, or BWOs, are small mayflies that often hatch in cool or cloudy weather.
- Caddis
- Caddis are small water insects. The adults look a little like tiny moths.
- Dry-dropper
- A dry-dropper rig has a floating fly with an underwater fly tied below it.
- Emerger
- An emerger copies an insect as it rises from below the water toward the surface.
Why this call
Why this score
Public alertUse caution
A Flood Watch is active near this forecast point, so the score is capped until runoff, clarity, crossings, and road access are checked. NWS alert: Flood Watch issued September 12 at 2:21AM EDT until September 13 at 12:00PM EDT by NWS Mount Holly NJ.
Best mode nowUse caution
Wade: Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
FlowHelps
USGS shows 49 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1919-2024, 106 readings) show a typical middle range of 30 cfs to 60 cfs. Flow is within the typical range for this date, so weather, temperature, and access become the next checks.
SeasonHelps
Fall and winter: BWOs, midges, scuds, and small streamers in legal C&R water.
WeatherHelps
The current NWS air forecast is about 58F, and the next 24-hour high reaches about 78F. Mostly Clear.
Trip notes
Check these before you choose a reach.
Use RiverReports and USGS 01396500 near High Bridge together for trend context. Moderate stable flow is ideal. High water makes gorge wading dangerous, while low clear summer water means smaller flies, longer leaders, and stricter temperature discipline.
Skip the South Branch when Ken Lockwood Gorge rules are unclear, when flow makes the gorge unsafe, when warm weather pushes trout toward stress, or when obvious access is already crowded enough to flatten the experience.
Start by choosing the river style you want: Ken Lockwood Gorge for the signature technical walk-and-wade day, High Bridge for the clearest live-flow reference, or upstream area water when you need more room than the famous gorge can offer.
If the South Branch is crowded, too warm, or too high for the gorge, compare the Musconetcong or Pequest for other strong New Jersey trout options, or Flat Brook for a quieter small-river plan.
South Branch Raritan River access and rules.
Use these places as starting points. Open the access link below and check posted signs before you park or enter.
Before you go
New Jersey trout rules include Ken Lockwood Gorge TCA and other South Branch reach rules. Check current rules before fishing.
Where to access the river
Ken Lockwood Gorge
Headline trout reach with special fishing rule and crowding considerations.
High Bridge gauge reach
Primary live-flow reference and nearby access context.
Califon and Long Valley area
Broader upstream access context with section-by-section rules.
- Ken Lockwood Gorge parking and foot traffic can be limited. Have a secondary access plan.
- Rules change by reach, so do not assume the whole river follows one method or harvest rule.
- High water in the gorge can make wading unsafe even when the river looks fishable from the road.
Sources and report details
Official agencies and primary river operators come first. Secondary tools are labeled so you know what carries the most weight.
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
Flow and weather
Check the latest river reading and forecast before you leave.
Access and land
Check public entry points, land rules, and seasonal access changes.
More helpful links
Use these links for stocking, safety, and other local details.
See all 7 checked sources
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
What this source covers
Open the current rules and check the river section, season, and special limits.
What this source covers
Open the current rules and check the river section, season, and special limits.
Flow and weather
Check the latest river reading and forecast before you leave.
What this source covers
Open this page and check the latest safety advice before your trip.
What this source covers
Open this river reading to check the latest level, flow, and update time.
What this source covers
Open this river reading to check the latest level, flow, and update time.
Access and land
Check public entry points, land rules, and seasonal access changes.
What this source covers
Open the land or access page, then check signs before you park or enter.
More helpful links
Use these links for stocking, safety, and other local details.
What this source covers
Open this page for stocking or fish population information.
How this report was checked
How this report was checked
Reviewed byBlueStreamFly River Review Team
Trip guidance checked
What was checked: This report is maintained from current regulation, access, flow, weather, and public planning sources so anglers can make better trip decisions than a raw gauge or generic overview would allow.
Live measurements and forecasts keep their provider timestamps. Rules, access, and trip guidance use the source-review date shown here. BlueStreamFly planning advice is editorial interpretation, not an agency notice.
First-hand experience: BlueStreamFly does not claim a first-hand visit or local field test for this report unless a real contributor is explicitly named and linked.
Quick questions
What should I check first before fishing the South Branch Raritan River?
Check RiverReports or USGS at High Bridge, NJ trout rules, Ken Lockwood Gorge TCA rules, access notes, weather, and water temperature.
Are there special fishing rules on the South Branch Raritan River?
Yes. Ken Lockwood Gorge and other reaches have special trout rules that must be checked before fishing.
What flies should I bring for the South Branch Raritan River?
Bring the hatch-chart flies, a few confidence nymphs, and a streamer or warmwater box that matches the river's species. Then adjust for water temperature, clarity, and the insects or baitfish you actually see.
Can I wade the South Branch Raritan River?
Yes at normal flows in many areas, but gorge footing and high water require conservative wading.
When should I skip the South Branch Raritan River?
Skip it when flows are unsafe, water is too warm for trout, emergency closures are active, or legal access for the reach is not clear.