McGee Bend dam: Agatized Wood Rockhounding in Jasper County, Texas

Updated July 2026

McGee Bend dam is a mapped rockhounding spot in Jasper County, Texas. Reported finds include agatized wood. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Permission required
County: Jasper County
State: Texas
Nearest road: Sam Rayburn Parkway
Postcode: 75931
Coordinates: 31.05684, -94.10297

Geology at McGee Bend dam

This spot sits on Terrace deposits, mapped as sand that formed within roughly the last 3 million years. Petrified wood typically travels as tough float, and worked gravels like these are exactly where weathered pieces tend to collect.

Mapped unit: Terrace deposits
Age: 3 Ma to present (Pleistocene to Holocene)
Rock types: sand
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 McGee Bend dam

Best months: September to May. Typical highs run 94°F in midsummer and 61°F in midwinter, with winter lows near 41°F. Summer heat here is intense, so carry more water than you think you need and work the early morning.

Climate normals: NOAA 1991-2020 monthlies, SAM RAYBURN DAM station (0 mi away).

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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

Texas Parks and Wildlife Department
Bureau of Economic Geology — Texas geology
Big Bend National Park — Rules
Community submissions reviewed against published agency rules

Found at McGee Bend dam

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

Agatized Wood Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of McGee Bend dam.

Across the state line from McGee Bend dam

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

McGee Bend dam FAQ

Where is McGee Bend dam?+

McGee Bend dam is in Jasper County, Texas, at 31.05684, -94.10297. Nearest road: Sam Rayburn Parkway.

What rocks and minerals can you find at McGee Bend dam?+

McGee Bend dam is reported to produce Agatized Wood.

Is collecting allowed at McGee Bend dam?+

Permission required before collecting. Requires landowner or agency permission before any collecting. Do not enter without explicit authorization. Always confirm current rules with the managing agency before a trip.

What tools should I bring to McGee Bend dam?+

A rock hammer, sturdy gloves, and a padded bag cover petrified wood hunting. Most pieces are surface float, so walking slopes and washes beats digging.

When is the best time to visit McGee Bend dam?+

The most comfortable months at McGee Bend dam are September to May. Summer heat here is intense, so carry more water than you think you need and work the early morning.

How do I get to McGee Bend dam?+

Open the directions link to navigate to 31.05684, -94.10297 in Google Maps. The nearest road is Sam Rayburn Parkway.

More rockhounding in Texas

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Open McGee Bend dam on the map

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