Tessman Farm: Agatized Palm Wood Rockhounding in Karnes County, Texas

Updated June 2026

Tessman Farm is a mapped rockhounding spot in Karnes County, Texas. Reported finds include agatized palm wood. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Karnes County
State: Texas
Nearest road: FM 1344
Postcode: 78113
Coordinates: 28.91727, -98.13721

Geology at Tessman Farm

This spot sits on ground mapped as Jackson Group, undivided that formed roughly 56 to 34 million years ago. Petrified wood typically shows up as durable float on slopes and in washes cut into ground like this.

Mapped unit: Jackson Group, undivided
Age: 56–34 Ma (Eocene)
Elevation: 430 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 Tessman Farm

Best months: October to May. Typical highs run 96°F in midsummer and 65°F in midwinter, with winter lows near 39°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, FLORESVILLE station (15 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 Tessman Farm

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

Agatized Palm Wood

Nearby rockhounding spots

Other rockhounding spots within driving distance of Tessman Farm.

Tessman Farm FAQ

Where is Tessman Farm?+

Tessman Farm is in Karnes County, Texas, at 28.91727, -98.13721. Nearest road: FM 1344.

What rocks and minerals can you find at Tessman Farm?+

Tessman Farm is reported to produce Agatized Palm Wood.

Is collecting allowed at Tessman Farm?+

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 Tessman Farm?+

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 Tessman Farm?+

The most comfortable months at Tessman Farm are October 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 Tessman Farm?+

Open the directions link to navigate to 28.91727, -98.13721 in Google Maps. The nearest road is FM 1344.

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Open Tessman Farm on the map

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