Muskallonge Lake State Park: Granite & Chert Rockhounding in Luce County, Michigan

Plan your visit

Pay-to-dig site

County

Luce County

State

Michigan

Coordinates

46.67661, -85.62808

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

Land & collecting status

Pay-to-dig site

This is a fee-dig location. Hours, prices, and what you can keep vary by operator. Call ahead before driving out.

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 Muskallonge Lake State Park

Comfortable months (45 to 90°F highs)

Best months: April to October. Typical highs run 74°F in midsummer and 24°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, GRAND MARAIS 2 E station (15 mi away).

Geology at Muskallonge Lake State Park

This spot sits on Jacobsville Sandstone, mapped as 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

Jacobsville Sandstone

Age

1600–1000 Ma (Mesoproterozoic)

Rock types

sandstone

Elevation

630 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