Carnelian beach: Agate Nodule & Carnelian Rockhounding in Keweenaw County, Michigan

Plan your visit

Permission required before collecting

County

Keweenaw County

State

Michigan

Nearest road

Island Mine Trail

Coordinates

47.90471, -89.00383

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

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 Carnelian beach

Comfortable months (45 to 90°F highs)

Best months: April to October. Typical highs run 74°F in midsummer and 21°F in midwinter, with winter lows near 1°F.

Climate normals: NOAA 1991-2020 monthlies, GRAND PORTAGE station (32 mi away).

Geology at Carnelian beach

This spot sits on Copper Harbor Conglomerate, mapped as conglomerate and sandstone that formed roughly 1600 to 1000 million years ago. Tough silica like agate, jasper, and chert typically weathers out of beds like these and collects as float in drainages and on deflation surfaces.

Mapped unit

Copper Harbor Conglomerate

Age

1600–1000 Ma (Mesoproterozoic)

Rock types

conglomerate and sandstone

Elevation

590 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.

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

• Michigan DNR, Rockhounding rules
• Michigan Geological Survey
• Isle Royale National Park, Rules
• Community submissions reviewed against published agency rules