Green Island: Celestite Rockhounding in Ottawa County, Ohio

Updated June 2026

Green Island is a mapped rockhounding spot in Ottawa County, Ohio. Reported finds include celestite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Ottawa County
State: Ohio
Nearest road: Old Lighthouse Walkway
Postcode: 43456
Coordinates: 41.64552, -82.86533

Geology at Green Island

This spot sits on Salina Group, mapped as dolostone that formed roughly 445 to 420 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: Salina Group
Age: 445–420 Ma (Silurian)
Rock types: dolostone
Elevation: 620 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 Green Island

Best months: March to November. Typical highs run 82°F in midsummer and 34°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, SANDUSKY station (16 mi away).

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.

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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Green Island

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

Celestite Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Green Island.

Across the state line from Green Island

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

William C. Sterling State ParkMonroe County, Michigan · 31 mi away

Green Island FAQ

Where is Green Island?+

Green Island is in Ottawa County, Ohio, at 41.64552, -82.86533. Nearest road: Old Lighthouse Walkway.

What rocks and minerals can you find at Green Island?+

Green Island is reported to produce Celestite.

Is collecting allowed at Green Island?+

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 Green Island?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Green Island?+

The most comfortable months at Green Island are March to November.

How do I get to Green Island?+

Open the directions link to navigate to 41.64552, -82.86533 in Google Maps. The nearest road is Old Lighthouse Walkway.

More rockhounding in Ohio

See all 38 Ohio spots →

Open Green Island on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.