South Branch Raritan River
New Jersey · Hunterdon County — Budd Lake to Clinton, Ken Lockwood Gorge
Brown TroutRainbow TroutBrook Trout
Top Fishing Locations on South Branch Raritan River
Ken Lockwood Gorge — Special Regulations Section
Ken Lockwood Gorge is the crown jewel of New Jersey trout fishing — a 2.5-mile catch-and-release stretch through a stunning hemlock-lined gorge named for Newark Evening News outdoor columnist Kenneth F. Lockwood. The 563-acre Wildlife Management Area protects some of the finest wild brown trout water in the mid-Atlantic, with fish documented to exceed 7 pounds. The boulder-strewn pocket water of the Gorge demands technical nymphing and precise dry fly presentations. Access via the Gorge road — cars are prohibited and the road serves as the trail. This is the most popular and most productive stretch on the river. Best seasons are spring Hendrickson and Sulphur hatches and fall when the big browns get aggressive.
💧 Ideal flow: 50 to 200 CFS for comfortable wading in the Gorge. The boulder pocket water becomes difficult to navigate safely above 300 CFS. Low summer flows can push fish into the deeper pools and require smaller patterns and lighter tippets. Check the High Bridge gauge before making the drive.
📊 Get Location Flow Report
Long Valley to Califon — Dry Fly Water
Above the Gorge, the river meanders through Long Valley to Califon with excellent meadow and riffle sections that offer some of the best dry fly opportunities on the South Branch. This water is stocked with rainbows and has good populations of holdover and wild brown trout. The more open character of this section allows for longer casts and the slower meandering pools demand stealth and careful approaches. Access is good via Route 513 through Long Valley with multiple roadside pulloffs.
💧 Ideal flow: 40 to 180 CFS for the meadow sections. Lower flows concentrate fish in the pools and bends. This section is particularly productive during early morning and evening hatch activity from late April through June when Hendrickson and Sulphur hatches produce consistent surface activity.
📊 Get Location Flow Report
High Bridge to Clinton — Lower Trout Water
The lower trout water from High Bridge downstream through Clinton holds stocked rainbows and some brown trout through the cooler months. This section is more accessible and less technical than the Gorge, making it a good option for anglers new to the river. The old mill dam site near Clinton creates an interesting pool that holds fish through the season. Below Clinton the river warms in summer and transitions toward warmwater species — trout fishing is best in this section from March through June and again in October and November.
💧 Ideal flow: 60 to 250 CFS. This section is more tolerant of flow variation than the technical Gorge water. Spring and fall are the prime windows when water temperatures are in the optimal 45-60 degree range for trout activity.
📊 Get Location Flow Report
About South Branch Raritan River Fishing
The South Branch of the Raritan River is the finest trout fishery in New Jersey and one of the most underappreciated wild trout rivers in the mid-Atlantic. The river flows 42 miles from Budd Lake in Morris County through Hunterdon County's rolling hills and farmland before meeting the North Branch to form the main stem Raritan. The upper reaches hold small wild reproducing brown and brook trout in the limestone spring-fed headwaters. The signature section is Ken Lockwood Gorge — a 2.5-mile catch-and-release stretch through a hemlock-lined gorge that holds wild brown trout to 7 pounds and represents some of the finest nymphing water in New Jersey. The river is within an hour of millions of Northeast anglers who often overlook it for more distant destinations.
Best Time to Fish South Branch Raritan River
Spring is prime. The Hendrickson hatch from late April through mid-May is the signature event in the Gorge — fish that have been dormant all winter come to the surface aggressively in the classic late morning to early afternoon window. Sulphur hatches from mid-May through June produce excellent evening dry fly fishing. Summer is challenging as water temperatures rise in the lower sections, but the Gorge stays cooler thanks to the hemlock canopy and spring inputs. Fall from September through November brings the best streamer and nymph fishing as brown trout get aggressive. Spring and fall are the windows when the wild browns in the Gorge are most catchable.
Species
Wild brown trout are the highlight species in the Ken Lockwood Gorge section — self-sustaining wild fish with a few genuine trophies exceeding 7 pounds documented in DNR surveys. Native brook trout exist in the Claremont headwaters area in small numbers. Rainbow trout are stocked throughout the river from spring through fall with some holdovers. The Gorge special regulations area protects the wild brown trout population and produces the best quality fishing.
Access and Regulations
Ken Lockwood Gorge: 2.5-mile catch-and-release, artificial lures and flies only, year-round. Access via the Gorge road off County Route 513 — no vehicle access, walk in only. Long Valley to Califon: standard regulations with stocking, good access via Route 513. High Bridge to Clinton: standard regulations, multiple access points along Route 31 and local roads. New Jersey fishing license required. USGS gauge near High Bridge provides current flow data.
Live River Data
Streamflow data is pulled in real time from the USGS National Water Information System. The South Branch Raritan is a freestone river that responds to rainfall — give it 24 to 48 hours to clear after significant rain events. The gauge near High Bridge provides the most relevant flow data for the Ken Lockwood Gorge and lower river sections.