The Altamont 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.
Altamont’s center stands about 620 ft above sea level. Within three miles the land runs from 580 ft to 660 ft, a difference of 80 ft: gently rolling country.
Under the town center the state geologic map shows Mattoon Formation (shale), from the Late Pennsylvanian, 304 to 307 million years old.
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.
Shale. Age: Late Pennsylvanian, 304 to 307 million years old. About 24 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 Altamont reaches the Gulf of America by way of the Little Wabash, the Ohio and the Mississippi: about 1,320 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Altamont; river miles along the main stem, rounded.