Best spot

Guilford & East Haven: Agate Rockhounding in South Central Connecticut Planning Region, Connecticut

Updated July 2026

The Guilford and East Haven shoreline yields water-worn agate, jasper, and quartz pebbles carried in as glacial erratics and reworked by Long Island Sound, a long-documented occurrence in Connecticut locality guides. Chaffinch Island Park in Guilford is the most openly accessible point, a free town park with a rocky tidal shorefront. Finds are small tumbled beach stones rather than outcrop material, best after storms at low tide. Reported finds include agate. Below: coordinates, access notes, nearby spots, and trip-planning links.

Guilford & East Haven photos

Public image records connected to this spot or its reported material.

1 photo

Long Island Sound shoreline on the New Haven County coast near East Haven, Connecticut

Quick details

Access: Public area
County: South Central Connecticut Planning Region
State: Connecticut
Nearest road: Towner Swamp Road
Postcode: 06437
Coordinates: 41.30202, -72.74609

Geology at Guilford & East Haven

This spot sits on Waterford Group plus Stony Creek Granite Gneiss plus Narragansett Pier Granite, mapped as granite and gneiss that formed roughly 1000 to 250 million years ago. Plutonic rock like this weathers slowly into grus and boulders, and the most productive collecting is typically in weathered zones and drainages.

Mapped unit: Waterford Group plus Stony Creek Granite Gneiss plus Narragansett Pier Granite
Age: 1000–250 Ma (Neoproterozoic to Permian)
Rock types: granite and gneiss
Elevation: 110 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Best time to visit Guilford & East Haven

Best months: March to November. Typical highs run 82°F in midsummer and 38°F in midwinter, with winter lows near 23°F.

Climate normals: NOAA 1991-2020 monthlies, NEW HAVEN TWEED AP station (8 mi away).

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Guilford & East Haven

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Agate Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Guilford & East Haven.

Across the state line from Guilford & East Haven

Guilford & East Haven is close enough to the Connecticut border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Guilford & East Haven FAQ

Where is Guilford & East Haven?+

Guilford & East Haven is in South Central Connecticut Planning Region, Connecticut, at 41.30202, -72.74609. Nearest road: Towner Swamp Road.

What rocks and minerals can you find at Guilford & East Haven?+

Guilford & East Haven is reported to produce Agate.

Is collecting allowed at Guilford & East Haven?+

Generally open to casual rockhounding. Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Guilford & East Haven?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Guilford & East Haven?+

The most comfortable months at Guilford & East Haven are March to November.

How do I get to Guilford & East Haven?+

Open the directions link to navigate to 41.30202, -72.74609 in Google Maps. The nearest road is Towner Swamp Road.

More rockhounding in Connecticut

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