St. Croix River at Grand Falls Flowage: Gold Prospecting in Washington County, Maine

Check locallyBest spot3 mineralsWashington County, MaineUpdated July 2026

Minerals reported: 3
Elevation: 200 ft
Best months: April to November

The Maine Geological Survey lists the St. Croix River at Baileyville among the state's recreational gold-panning streams, where the gold is very fine flour gold thought to be shed from nearby base-metal mineralization. A state-owned boat access on the Grand Falls Flowage gives free public entry to the water. Garnet and magnetite occur in the same black sand. Reported finds include gold, garnet, magnetite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Confirm rules before collecting

County: Washington County
State: Maine
Coordinates: 45.25130, -67.52300

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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

Confirm rules before collecting

Land status here is not confirmed. Verify with the managing agency before collecting, federal, state, and tribal rules differ.

Access note: Use the free state boat access on the Grand Falls Flowage at Baileyville. The river is an international boundary water, so pan only on the Maine side from the public water and leave the banks undisturbed; hand panning needs no permit.

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 St. Croix River at Grand Falls Flowage

28°J

31°F

39°M

52°A

64°M

74°J

80°J

79°A

71°S

58°O

46°N

35°D

Comfortable months (45 to 90°F highs)

Best months: April to November. Typical highs run 80°F in midsummer and 28°F in midwinter, with winter lows near 13°F.

Climate normals: NOAA 1991-2020 monthlies, WOODLAND station (9 mi away).

Geology at St. Croix River at Grand Falls Flowage

This spot sits on Flume Ridge Formation, mapped as graywacke that formed roughly 485 to 420 million years ago. In sedimentary country like this, any placer gold is typically recycled from older gravels, concentrating again in modern stream beds.

Mapped unit: Flume Ridge Formation
Age: 485–420 Ma (Ordovician to Silurian)
Rock types: graywacke
Elevation: 200 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.

State guidance last verified: April 1, 2026

Maine Geological Survey
Maine Mineral & Gem Museum
Acadia National Park rules
Community submissions reviewed against published agency rules

Found at St. Croix River at Grand Falls Flowage

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 St. Croix River at Grand Falls Flowage.

PerryWashington County, Maine · 27 mi awayAnalcime, Calcite, Datolite
Gleason CoverWashington County, Maine · 30 mi awayJasper
Lubec Lead MineWashington County, Maine · 37 mi awayAnglesite, Bornite, Calcite
Jasper BeachWashington County, Maine · 44 mi awayRed Jasper
Tunk MountainHancock County, Maine · 51 mi awaySmoky Quartz, Feldspar, Hornblende
Catherine Mountain (Donnell Pond)Hancock County, Maine · 52 mi awayMolybdenite, Scheelite, Fluorapatite
Warren Nickel ProspectKnox County, Maine · 113 mi awayPyrrhotite, Chalcopyrite

St. Croix River at Grand Falls Flowage FAQ

Where is St. Croix River at Grand Falls Flowage?+

St. Croix River at Grand Falls Flowage is in Washington County, Maine, at 45.25130, -67.52300.

What rocks and minerals can you find at St. Croix River at Grand Falls Flowage?+

St. Croix River at Grand Falls Flowage is reported to produce Gold, Garnet, Magnetite.

Is collecting allowed at St. Croix River at Grand Falls Flowage?+

Confirm rules before collecting. Land status here is not confirmed. Verify with the managing agency before collecting, federal, state, and tribal rules differ. Always confirm current rules with the managing agency before a trip.

What tools should I bring to St. Croix River at Grand Falls Flowage?+

A gold pan, a classifier screen, a small shovel, and a snuffer bottle cover the basics. Motorized equipment and sluices fall under separate rules in most states, so start with hand tools.

When is the best time to visit St. Croix River at Grand Falls Flowage?+

The most comfortable months at St. Croix River at Grand Falls Flowage are April to November.

How do I get to St. Croix River at Grand Falls Flowage?+

Open the directions link to navigate to 45.25130, -67.52300 in Google Maps. Some spots are remote, so check road conditions before driving out.

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