The Sanderson plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Sanderson’s center stands about 2,790 ft above sea level. Within three miles the land runs from 2,660 ft to 3,300 ft, a difference of 640 ft: hilly country. The highest named summit within 15 miles is Two Top Mountain, about 3,460 ft, 12 miles northwest.
Under the town center the state geologic map shows Quaternary deposit, undivided (coarse-detrital, fine-detrital), from the Quaternary, less than 2.6 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 14×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 8 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 8 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 6 mi of the line.
Limestone. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 0.4 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Sanderson reaches the Gulf of America by way of Sanderson Creek and the Rio Grande: about 730 river miles.
Lakes on the way: Paz Ramirez Lake and Amistad Reservoir.
270 miles of the trip are on the Rio Grande.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Sanderson; river miles along the main stem, rounded.