The Pine 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.
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Pine Grove’s center stands about 2,430 ft above sea level. Within three miles the land runs from 2,260 ft to 3,980 ft, a difference of 1,720 ft: steep hill country. The highest named summit within 15 miles is Copper Butte, about 7,130 ft, 11 miles east-northeast.
Under the town center the state geologic map shows Eocene-Oligocene volcanic rocks (andesite, basalt), from the Eocene to Oligocene, 23 to 56 million years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 5×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Granite. Age: Precambrian to Eocene. About 6 mi of the line.
Andesite, basalt. Age: Eocene to Oligocene, 23 to 56 million years old. About 4 mi of the line.
Granite, granodiorite, trondhjemite. Age: Late Cretaceous to Eocene, 34 to 100 million years old. About 4 mi of the line.
Graywacke, quartzite. Age: Ordovician, 445 to 487 million years old. About 3 mi of the line.
Metasedimentary. Age: Devonian to Permian, 273 to 422 million years old. About 3 mi of the line.
Quartz-monzonite, granite, basalt. Age: Eocene to Early Pliocene, 3.6 to 56 million years old. About 2 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 2 smaller units along the line are not listed.
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 Pine Grove reaches the Pacific Ocean by way of the Sanpoil and the Columbia: about 670 river miles.
Lake on the way: Lake Umatilla.
330 miles of the trip are on the Columbia.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Pine Grove; river miles along the main stem, rounded.
