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Sam Houston National Forest (Double Lake): Petrified Palm Wood & Petrified Wood Rockhounding in San Jacinto County, Texas

Updated June 2026

Sam Houston National Forest carries petrified palm wood, the official Texas state stone since 1969, along with agate, jasper, and chalcedony weathered from young Gulf Coastal Plain gravels. The US Forest Service permits personal collection of common lapidary minerals and petrified wood here under a free use permit. Vertebrate fossils and artifacts are excluded. Reported finds include petrified palm wood, petrified wood, agate, jasper, carnelian. Below: coordinates, access notes, nearby spots, and trip-planning links.

Sam Houston National Forest (Double Lake) photos

Public image records connected to this spot or its reported material.

1 photo

Polished petrified palm wood showing its rod pattern, the Texas state stone found in Sam Houston National Forest

Quick details

Access: Public area
County: San Jacinto County
State: Texas
Coordinates: 30.54855, -95.13058

Geology at Sam Houston National Forest (Double Lake)

This spot sits on Willis Formation, mapped as coarse alluvium and fine alluvium that formed roughly 5 to 3 million years ago. Petrified wood typically travels as tough float, and worked gravels like these are exactly where weathered pieces tend to collect.

Mapped unit: Willis Formation
Age: 5–3 Ma (Pliocene)
Rock types: coarse alluvium and fine alluvium
Elevation: 310 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 Sam Houston National Forest (Double Lake)

Best months: September to June. Typical highs run 91°F in midsummer and 60°F in midwinter, with winter lows near 38°F.

Climate normals: NOAA 1991-2020 monthlies, CLEVELAND station (13 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.

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 Sam Houston National Forest (Double Lake)

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 Sam Houston National Forest (Double Lake).

Sam Houston National Forest (Double Lake) FAQ

Where is Sam Houston National Forest (Double Lake)?+

Sam Houston National Forest (Double Lake) is in San Jacinto County, Texas, at 30.54855, -95.13058.

What rocks and minerals can you find at Sam Houston National Forest (Double Lake)?+

Sam Houston National Forest (Double Lake) is reported to produce Petrified Palm Wood, Petrified Wood, Agate, Jasper, Carnelian.

Is collecting allowed at Sam Houston National Forest (Double Lake)?+

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 Sam Houston National Forest (Double Lake)?+

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 Sam Houston National Forest (Double Lake)?+

The most comfortable months at Sam Houston National Forest (Double Lake) are September to June.

How do I get to Sam Houston National Forest (Double Lake)?+

Open the directions link to navigate to 30.54855, -95.13058 in Google Maps. Some spots are remote, so check road conditions before driving out.

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