The McLendon-Chisholm 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.
McLendon-Chisholm’s center stands about 500 ft above sea level. Within three miles the land runs from 470 ft to 570 ft, a difference of 100 ft: gently rolling country.
Under the town center the state geologic map shows Marlbrook Marl (clay), from the Late Cretaceous, 66 to 72 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.
Clay. Age: Late Cretaceous, 66 to 72 million years old. About 13 mi of the line.
Fine-detrital, coarse-detrital. Age: Holocene, less than 12,000 years old. About 6 mi of the line.
Claystone. Age: Late Cretaceous, 66 to 72 million years old. About 6 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 McLendon-Chisholm reaches Galveston Bay and the Gulf of America by way of Brushy Creek, Big Brushy Creek, Kings Creek, Cedar Creek and the Trinity: about 410 river miles.
Lakes on the way: Woodlands Golf Course Lake and Cedar Creek Reservoir.
150 miles of the trip are on the Trinity.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of McLendon-Chisholm; river miles along the main stem, rounded.