Adams Brook: Serpentine & Quartz Rockhounding in Windham County, Vermont

Public accessBest spot5 mineralsWindham County, VermontUpdated July 2026

Minerals reported: 5
Elevation: 1,040 ft
Best months: April to November

Adams Brook in the far southeast corner of Vermont tumbles varicolored serpentine boulders with red, orange, and green agate and clear quartz, a distinctive mix for the state. Tourmaline and garnet also turn up in the streambed. It is a genuine Vermont serpentine and agate locality near the Harriman Reservoir in Whitingham. Reported finds include serpentine, quartz, red agate, orange agate, green agate. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Generally open to casual rockhounding

County: Windham County
State: Vermont
Nearest road: Adams Hill Road
Postcode: 05351
Coordinates: 42.95077, -72.75817

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Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

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.

Access note: Collecting is in and along the brook where the road crosses it. Land ownership on the banks is not clearly public, so confirm the section is not posted and get permission where needed before collecting. Take surface stream material only.

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.

Best time to visit Adams Brook

31°J

34°F

41°M

53°A

65°M

73°J

78°J

77°A

71°S

59°O

47°N

37°D

Comfortable months (45 to 90°F highs)

Best months: April to November. Typical highs run 78°F in midsummer and 31°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, ROWE 3NE station (16 mi away), adjusted for elevation.

Geology at Adams Brook

This spot sits on Meta-ultramafic rocks - undifferentiated, mapped as metadunite, metaperidotite, and serpentinite that formed roughly 1000 to 485 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.

Mapped unit: Meta-ultramafic rocks - undifferentiated
Age: 1000–485 Ma (Neoproterozoic to Cambrian)
Rock types: metadunite, metaperidotite, and serpentinite
Elevation: 1,040 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.

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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.

Vermont Geological Survey
Green Mountain National Forest
Vermont State Parks, Camp Plymouth
Community submissions reviewed against published agency rules

Found at Adams Brook

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

Nearby rockhounding spots

Other rockhounding spots within driving distance of Adams Brook.

Across the state line from Adams Brook

Adams Brook is close enough to the Vermont border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Park HillCheshire County, New Hampshire · 15 mi awayStaurolite
Spofford LakeCheshire County, New Hampshire · 16 mi awayFluorite
HinsdaleCheshire County, New Hampshire · 19 mi awayPink Rhodonite
Davis MineFranklin County, Massachusetts · 19 mi awayChalcopyrite, Pyrite
Derry HillCheshire County, New Hampshire · 21 mi awayBeryl, Rose Quartz
Chickering MineCheshire County, New Hampshire · 21 mi awayPurpurite, Heterosite, Childrenite

Adams Brook FAQ

Where is Adams Brook?+

Adams Brook is in Windham County, Vermont, at 42.95077, -72.75817. Nearest road: Adams Hill Road.

What rocks and minerals can you find at Adams Brook?+

Adams Brook is reported to produce Serpentine, Quartz, Red Agate, Orange Agate, Green Agate.

Is collecting allowed at Adams Brook?+

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 Adams Brook?+

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 Adams Brook?+

The most comfortable months at Adams Brook are April to November.

How do I get to Adams Brook?+

Open the directions link to navigate to 42.95077, -72.75817 in Google Maps. The nearest road is Adams Hill Road.

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