The Oglala 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
Oglala’s center stands about 2,990 ft above sea level. Within three miles the land runs from 2,930 ft to 3,350 ft, a difference of 420 ft: hilly country. The highest named summit within 15 miles is Hubbard Butte, about 3,770 ft, 15 miles south-southeast.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 26×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone, sandstone. Age: Oligocene to Miocene, 5.3 to 34 million years old. About 10 mi of the line.
Claystone, siltstone, sandstone. Age: Eocene to Oligocene, 23 to 56 million years old. About 7 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 4 mi of the line.
Coarse-detrital, clay. Age: Quaternary, less than 2.6 million years old. About 3 mi of the line.
Silt, sand. Age: Quaternary, less than 2.6 million years old. About 0.3 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 0.3 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 Oglala reaches the Gulf of America by way of White Clay Creek, the White River, the Missouri and the Mississippi: about 2,530 river miles.
Lakes on the way: Lake Francis Case and Lewis and Clark Lake.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Oglala; river miles along the main stem, rounded.
