What Four Mile River offers and when to fish it

Four Mile River is a tidal estuary that runs roughly three miles from its mouth at the Connecticut River near Old Lyme to its headwaters inland. The river holds both smallmouth and largemouth bass, along with catfish and occasional stripers during spring and fall. The lower two miles are brackish and influenced by tide; the upper mile freshens considerably. Most anglers work the middle section where the salinity gradient creates structure that holds fish year-round.

Seasonal timing matters more here than on freshwater rivers because tide controls access and fish behavior. Spring (April through May) brings spawning smallmouth into shallow flats and woody cover. Summer is slow in the main channel but productive early and late in the day along shaded banks. Fall (September through October) is the most consistent season—water cools, baitfish move, and bass feed aggressively. Winter is fishable but requires patience and slow presentations in deeper holes.

Key Takeaways

  • Four Mile River is a tidal estuary with brackish lower sections and fresher upper reaches, holding smallmouth and largemouth bass year-round.
  • The middle section between the Connecticut River mouth and the freshwater transition is the most productive zone for consistent access and structure.
  • Tide timing is critical—fish the incoming tide on shallow flats and the slack or outgoing tide in deeper holes and channels.
  • Spring spawning and fall feeding periods are the most reliable times to catch numbers; summer requires early morning or evening fishing.
  • Public access is limited; launch from Old Lyme town ramp or fish from shore along Route 156 where it crosses the river.

Access and launch points

The Old Lyme town boat ramp is your primary access. It sits on the Connecticut River side, just south of where Four Mile River enters. The ramp is concrete, well-maintained, and has parking for roughly a dozen vehicles. There is no fee for residents; non-residents should check with the town office, as fees vary by season. The ramp can get crowded on weekends, especially during spring and fall.

If you do not have a boat, Route 156 crosses Four Mile River inland, roughly two miles from the mouth. There is limited shoulder parking on both sides of the bridge. From here you can wade or fish from shore, though the banks are steep and muddy in places. This spot works best at low tide when you can access more of the riverbed. The upper reaches above Route 156 are mostly private property; stick to the public bridge area.

Structure and where bass hold

The lower estuary (first mile from the Connecticut River) is wide and relatively open, with soft bottom and scattered submerged logs. This zone is most productive on the incoming tide when baitfish move in and bass follow. Fish the edges where current breaks and along any visible wood. Largemouth tend to hold tighter to cover here; smallmouth roam more freely in the channel.

The middle section (mile one to two) is where most anglers focus. The river narrows, and the banks become more defined with overhanging trees, root wads, and occasional rock outcrops. This is prime smallmouth habitat. Work the outside bends where current scours deeper holes, and cast parallel to the banks rather than perpendicular. The salinity here is mixed, so both species are present, though smallmouth dominate.

The upper reach (mile two to three) freshens considerably and holds largemouth in the shallows and around submerged vegetation if present. This section is less tidal influence and more like a traditional river. It is harder to reach by boat at low tide because the channel shallows, but it can be productive on high water.

Seasonal patterns and what to throw

Spring (April–May) is spawning season. Smallmouth move to shallow flats with sand or gravel bottom, usually in two to six feet of water. Largemouth seek woody cover and shallow bays. Fish small jigs (1/8 to 1/4 ounce), soft plastics in natural colors, and crankbaits that mimic shad. Early morning is best; fish slow and deliberately around cover.

Summer (June–August) is tough midday but productive at dawn and dusk. Bass retreat to deeper holes and shaded banks. Switch to topwater early, then move to deeper presentations—tubes, swimbaits, and soft plastics worked along drop-offs. The incoming tide in early morning often triggers feeding before the sun heats the water.

Fall (September–October) is the most reliable season. Water cools, baitfish concentrate, and bass feed aggressively throughout the day. Throw larger swimbaits (3 to 4 inches), topwater plugs, and crankbaits. The outgoing tide can be as productive as the incoming because baitfish are pushed toward deeper water and bass intercept them. Fish from mid-morning through late afternoon.

Winter (November–March) requires patience. Bass slow considerably and hold in the deepest holes. Fish small jigs and soft plastics very slowly. The incoming tide is usually more productive than outgoing because it brings slightly warmer water from the Connecticut River. Expect fewer fish but larger individuals.

Tide timing and current patterns

Four Mile River is tidal, and understanding the cycle is essential. The incoming tide (flood) pushes water and baitfish into the estuary, triggering feeding. Fish the shallow flats and banks during the first two hours of incoming tide. The slack water at high tide is often slow, but the transition from slack to outgoing can be productive as current picks up again.

The outgoing tide (ebb) pushes water and baitfish toward the Connecticut River. Fish the deeper holes and channel edges during outgoing tide. Bass position themselves to intercept baitfish moving seaward. The last hour of outgoing tide, just before slack, is often excellent. Avoid fishing the middle of the outgoing tide when current is strongest and fish are less likely to chase.

Tide tables for the Connecticut River apply here. Check NOAA tide predictions for Old Lyme or the Connecticut River mouth before you go. A typical tidal cycle is roughly six hours of incoming, six hours of outgoing, with slack periods in between. Plan your trip around the incoming tide if you want to fish shallow water; plan around outgoing if you want to fish deeper structure.

What to expect and common challenges

Four Mile River is not a high-volume fishery. You will catch fish, but not in the numbers you might find on larger Connecticut rivers. The trade-off is that the fish tend to be healthy and the pressure is light. Expect to land three to six bass on a good day, with occasional larger fish (16 inches or better) in fall and spring.

Silt and mud are common on the bottom, especially in the lower estuary. This makes wading difficult and can cloud the water after heavy rain. The brackish water also means fewer aquatic insects and less natural forage than freshwater rivers, so baitfish and shad are the primary food source. Fish accordingly with swimbaits and shad-pattern crankbaits.

Boat traffic can be heavy on weekends, especially in summer. The Connecticut River mouth sees commercial and recreational traffic, and some of that spills into Four Mile River. Fish early morning or weekday if you want solitude. The river is narrow enough that a few boats can make it feel crowded.

Gear and tackle recommendations

A 6-foot to 6.5-foot medium-power spinning rod works well for most Four Mile River fishing. Pair it with 10- to 15-pound braided line for better sensitivity and hookset in the tidal current. A fluorocarbon leader (12 to 20 pounds) helps in the clearer upper reaches. If you prefer baitcasting, a 7-foot medium-heavy rod gives you better accuracy in tight cover.

Keep your tackle simple. Jigs (1/8 to 3/8 ounce) in black, brown, and natural colors work year-round. Soft plastics in 3- to 5-inch lengths, crankbaits that dive 4 to 8 feet, and topwater plugs cover most situations. Swimbaits in shad patterns are excellent in fall. Bring a few spinnerbaits for murky water after rain. You do not need a large tackle box—this river rewards focus and repetition over variety.

Frequently Asked Questions

Can I fish Four Mile River in winter?

Yes, but it is slow. Bass move to the deepest holes and feed less frequently. Fish small jigs and soft plastics very slowly, and focus on the incoming tide when water temperature is slightly higher. Expect fewer fish but a chance at larger individuals.

What is the difference between the lower and upper river?

The lower estuary (first mile) is brackish, wide, and open with soft bottom. The upper reaches are fresher, narrower, and have more defined banks and cover. Smallmouth dominate the middle section; largemouth are more common in the upper freshwater zone.

Do I need a boat to fish Four Mile River?

No. You can fish from the Route 156 bridge area on foot, though access is limited and the banks are steep. A small boat or kayak gives you much better access to productive structure and allows you to follow the tide. The town ramp makes launching easy.

What size bass should I expect?

Most fish run 10 to 14 inches. Spring and fall produce occasional fish in the 16- to 18-inch range. The river is not known for trophy bass, but it is consistent for healthy, hard-fighting smallmouth and largemouth in the 12-inch class.

How does tide affect fishing success?

Tide controls where fish feed and how aggressive they are. The incoming tide is usually most productive because it brings baitfish and triggers feeding. The outgoing tide can be good in deeper holes. Slack water (high or low tide) is typically slow. Check tide tables and plan your trip around the incoming tide for best results.