The Walnut Grove 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.
Mostly sunny
Mostly sunny; warmer
Partly cloudy
Sunny
Mostly sunny
Mostly sunny
Mostly sunny
Walnut Grove’s center stands about 380 ft above sea level. Within three miles the land runs from 340 ft to 510 ft, a difference of 170 ft: gently rolling country.
Under the town center the state geologic map shows Kosciusko formation (sand, clay), from the Eocene, 34 to 56 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.
Sand, clay. Age: Eocene, 34 to 56 million years old. About 10 mi of the line.
Clay, sand. Age: Eocene, 34 to 56 million years old. About 8 mi of the line.
Marl, sand. Age: Eocene, 34 to 56 million years old. About 5 mi of the line.
Clay. Age: Eocene, 34 to 56 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 Walnut Grove reaches the Gulf of America by way of Tuscolameta Creek and the Pearl: about 370 river miles.
Lake on the way: Cypress Lake.
310 miles of the trip are on the Pearl.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Walnut Grove; river miles along the main stem, rounded.
