Needle Peak: Agate Rockhounding in Presidio County, Texas

Quick details

Access

Permission required

County

Presidio County

State

Texas

Coordinates

29.42831, -103.81041

Geology at Needle Peak

This spot sits on Tesnus Formation, mapped as sandstone mudstone, sandstone, and black shale that formed roughly 360 to 300 million years ago. Tough silica like agate, jasper, and chert typically weathers out of beds like these and collects as float in drainages and on deflation surfaces.

Mapped unit

Tesnus Formation

Age

360–300 Ma (Mississippian to Pennsylvanian)

Rock types

sandstone mudstone, sandstone, and black shale

Elevation

4,420 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 Needle Peak

Best months: August to May. Typical highs run 91°F in midsummer and 61°F in midwinter, with winter lows near 29°F.

Climate normals: NOAA 1991-2020 monthlies, BIG BEND RCH SP station (9 mi away), adjusted for elevation.

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 Needle Peak

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

• AgateEncyclopedia →