Grand Traverse Lighthouse: Rockhounding in Leelanau County, Michigan

Quick details

Access

Check locally

County

Leelanau County

State

Michigan

Postcode

49674

Coordinates

45.21023, -85.54995

Geology at Grand Traverse Lighthouse

This spot sits on Traverse Group, mapped as limestone that formed roughly 395 to 385 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.

Mapped unit

Traverse Group

Age

395–385 Ma (Middle Devonian)

Rock types

limestone

Elevation

580 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 Grand Traverse Lighthouse

Best months: April to November. Typical highs run 76°F in midsummer and 29°F in midwinter, with winter lows near 19°F.

Climate normals: NOAA 1991-2020 monthlies, NORTHPORT 2W station (7 mi away), adjusted for elevation.

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.

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.

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