The Rosita 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.
Rosita’s center stands about 740 ft above sea level. Within three miles the land runs from 660 ft to 810 ft, a difference of 150 ft: gently rolling country. The highest named summit within 15 miles is Chapotal Hill, about 920 ft, 12 miles north-northeast.
Under the town center the state geologic map shows Uvalde Gravel, from the Late Pliocene to Pleistocene, less than 3.6 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Gravel. Age: Late Pliocene to Pleistocene, less than 3.6 million years old. About 6 mi of the line.
Black-shale. Age: Late Cretaceous, 66 to 72 million years old. About 5 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 2 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 1 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 Rosita reaches the Gulf of America by way of the Rio Grande: about 490 river miles.
Lake on the way: Paz Ramirez Lake.
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 Rosita; river miles along the main stem, rounded.