The St. Jo 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.
St. Jo’s center stands about 1,140 ft above sea level. Within three miles the land runs from 970 ft to 1,250 ft, a difference of 280 ft: rolling country. The highest named summit within 15 miles is Mount View, about 1,300 ft, 4 miles north.
Under the town center the state geologic map shows Antlers Sand (sandstone, claystone), from the Early Cretaceous, 100 to 145 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 37×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, claystone. Age: Early Cretaceous, 100 to 145 million years old. About 19 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 3 mi of the line.
Fine-detrital. Age: Holocene, less than 12,000 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.
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 St. Jo reaches Galveston Bay and the Gulf of America by way of the Elm Fork Trinity and the Trinity: about 570 river miles.
Lakes on the way: Woodlands Golf Course Lake and Lake Lewisville.
270 miles of the trip are on the Trinity.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of St. Jo; river miles along the main stem, rounded.