Allentown: Jasper & Chert Rockhounding in Lehigh County, Pennsylvania

Updated June 2026

Allentown is a mapped rockhounding spot in Lehigh County, Pennsylvania. Reported finds include jasper, chert. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Lehigh County
State: Pennsylvania
Nearest road: Skyline Drive
Postcode: 18103
Coordinates: 40.59736, -75.44122

Geology at Allentown

This spot sits on Felsic to mafic gneiss, mapped as gneiss that formed roughly 4600 to 540 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.

Mapped unit: Felsic to mafic gneiss
Age: 4600–540 Ma (Precambrian)
Rock types: gneiss
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 Allentown

Best months: March to November. Typical highs run 86°F in midsummer and 38°F in midwinter, with winter lows near 21°F.

Climate normals: NOAA 1991-2020 monthlies, ALLENTOWN LEHIGH VLY INTL AP station (4 mi away), adjusted for elevation.

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 Allentown

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 Allentown.

Across the state line from Allentown

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

Allentown FAQ

Where is Allentown?+

Allentown is in Lehigh County, Pennsylvania, at 40.59736, -75.44122. Nearest road: Skyline Drive.

What rocks and minerals can you find at Allentown?+

Allentown is reported to produce Jasper, Chert.

Is collecting allowed at Allentown?+

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 Allentown?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Allentown?+

The most comfortable months at Allentown are March to November.

How do I get to Allentown?+

Open the directions link to navigate to 40.59736, -75.44122 in Google Maps. The nearest road is Skyline Drive.

More rockhounding in Pennsylvania

See all 88 Pennsylvania spots →

Open Allentown on the map

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