The Hamilton 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.
Hamilton’s center stands about 910 ft above sea level. Within three miles the land runs from 710 ft to 940 ft, a difference of 230 ft: rolling country.
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 57×. 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, sandstone, siltstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 21 mi of the line.
Shale, siltstone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 1 mi of the line.
Dolostone, limestone. Age: Middle Mississippian to Late Mississippian, 324 to 347 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 Hamilton reaches the Gulf of America by way of Coal Creek, the Des Moines and the Mississippi: about 1,470 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Hamilton; river miles along the main stem, rounded.