The Throckmorton 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.
Showers likely
Showers likely
Mostly cloudy
Partly cloudy; warmer
Partly cloudy
Mostly cloudy
Partly cloudy
Throckmorton’s center stands about 1,350 ft above sea level. Within three miles the land runs from 1,250 ft to 1,440 ft, a difference of 190 ft: gently rolling country. The highest named summit within 15 miles is Hoover Mountain, about 1,580 ft, 15 miles southwest.
The section below crosses 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 38×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone-mudstone. Age: Permian, 252 to 299 million years old. About 7 mi of the line.
Gravel. Age: Pleistocene, less than 2.6 million years old. About 5 mi of the line.
Siltstone-mudstone. Age: Permian, 252 to 299 million years old. About 3 mi of the line.
Shale. Age: Permian, 252 to 299 million years old. About 3 mi of the line.
Limestone, shale. Age: Permian, 252 to 299 million years old. About 2 mi of the line.
Shale. Age: Permian, 252 to 299 million years old. About 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. 4 smaller units along the line are not listed.
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 Throckmorton reaches the Gulf of America by way of Elm Creek and the Brazos: about 820 river miles.
Lakes on the way: Possum Kingdom Lake and Lake Granbury.
550 miles of the trip are on the Brazos.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Throckmorton; river miles along the main stem, rounded.
