The Rockdale 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.
Chance of showers
Showers likely
Chance of showers
Sunny; warmer
Mostly cloudy
Partly cloudy
Partly cloudy
Rockdale’s center stands about 470 ft above sea level. Within three miles the land runs from 420 ft to 550 ft, a difference of 130 ft: gently rolling country. The highest named summit within 15 miles is Taylor Mountain, about 650 ft, 7 miles east.
Under the town center the state geologic map shows Calvert Bluff Formation (claystone), from the Late Paleocene to Early Eocene, 48 to 59 million years old.
The section below crosses 3 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.
Sand. Age: Paleocene, 56 to 66 million years old. About 13 mi of the line.
Claystone. Age: Late Paleocene to Early Eocene, 48 to 59 million years old. About 11 mi of the line.
Claystone. Age: Paleocene, 56 to 66 million years old. About 0.2 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 Rockdale reaches the Gulf of America by way of East Yegua Creek, Yegua Creek and the Brazos: about 320 river miles.
Lake on the way: Somerville Lake.
250 miles of the trip are on the Brazos.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Rockdale; river miles along the main stem, rounded.
