The Costilla 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.
Costilla’s center stands about 7,800 ft above sea level. Within three miles the land runs from 7,670 ft to 8,850 ft, a difference of 1,180 ft: steep hill country. The highest named summit within 15 miles is State Line Peak, about 12,860 ft, 13 miles east.
Under the town center the state geologic map shows Alluvium (unconsolidated), from the Pleistocene to Holocene, less than 0.1 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 4×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Unconsolidated. Age: Pleistocene to Holocene, less than 0.1 million years old. About 11 mi of the line.
Unconsolidated. Age: Pleistocene to Holocene, less than 2.6 million years old. About 5 mi of the line.
Granitic, gneiss. Age: Paleoproterozoic, 1.6 to 1.7 billion years old. About 4 mi of the line.
Basalt, andesite. Age: Pliocene, 2.6 to 5.3 million years old. About 3 mi of the line.
Unconsolidated. Age: Pleistocene to Holocene, less than 2.6 million years old. About 0.9 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 Costilla reaches the Gulf of America by way of Costilla Creek and the Rio Grande: about 1,730 river miles.
Lakes on the way: Paz Ramirez Lake, Amistad Reservoir, Elephant Butte Reservoir and Caballo Reservoir.
760 miles of the trip are on the Rio Grande.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Costilla; river miles along the main stem, rounded.