Castleton: Quartz & Tourmaline Rockhounding in Harford County, Maryland

Updated June 2026

Castleton is a mapped rockhounding spot in Harford County, Maryland. Reported finds include quartz, tourmaline. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Harford County
State: Maryland
Nearest road: Mason-Dixon Trail
Postcode: 21034
Coordinates: 39.68507, -76.21831

Geology at Castleton

This spot sits on ground mapped as water. Quartz crystals typically weather out of veins and pockets and end up in nearby soils and creek beds.

Mapped unit: water
Elevation: 160 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 Castleton

Best months: March to December. Typical highs run 87°F in midsummer and 40°F in midwinter, with winter lows near 24°F.

Climate normals: NOAA 1991-2020 monthlies, CONOWINGO DAM station (3 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 Castleton

Each chip 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 Castleton.

Across the state line from Castleton

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

Castleton FAQ

Where is Castleton?+

Castleton is in Harford County, Maryland, at 39.68507, -76.21831. Nearest road: Mason-Dixon Trail.

What rocks and minerals can you find at Castleton?+

Castleton is reported to produce Quartz, Tourmaline.

Is collecting allowed at Castleton?+

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 Castleton?+

A rock hammer, a small pry bar, gloves, and safety glasses cover most crystal ground. A screen helps in loose pocket soil, and newspaper protects points on the way out.

When is the best time to visit Castleton?+

The most comfortable months at Castleton are March to December.

How do I get to Castleton?+

Open the directions link to navigate to 39.68507, -76.21831 in Google Maps. The nearest road is Mason-Dixon Trail.

More rockhounding in Maryland

See all 43 Maryland spots →

Open Castleton on the map

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