The Crystal Lake 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.
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Showers likely
Crystal Lake’s center stands about 1,280 ft above sea level. Within three miles the land runs from 1,200 ft to 1,340 ft, a difference of 140 ft: gently rolling country. The highest named summit within 15 miles is Pilot Knob, about 1,440 ft, 12 miles east.
Under the town center the state geologic map shows Lime Creek Formation (shale, limestone, dolostone), from the Late Devonian, 374 to 384 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.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 8 mi of the line.
Limestone, dolostone. Age: Middle Devonian to Late Devonian, 374 to 388 million years old. About 8 mi of the line.
Shale, limestone, dolostone. Age: Late Devonian, 374 to 384 million years old. About 8 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 Crystal Lake reaches the Gulf of America by way of the West Branch Iowa, the Iowa and the Mississippi: about 1,760 river miles.
1,410 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Crystal Lake; river miles along the main stem, rounded.
