The Grover 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.
Grover’s center stands about 6,150 ft above sea level. Within three miles the land runs from 6,000 ft to 8,500 ft, a difference of 2,500 ft: mountain country. The highest named summit within 15 miles is Mount Fitzpatrick, about 10,840 ft, 9 miles east-southeast.
Under the town center the state geologic map shows Alluvium and Colluvium (clay, silt, sand), from the Pleistocene to Holocene, less than 2.6 million years old.
The section below crosses 13 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 4×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Clay, silt, sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 6 mi of the line.
Sandstone, shale. Age: Cretaceous, 66 to 145 million years old. About 5 mi of the line.
Limestone, dolostone. Age: Late Devonian to Carboniferous, 324 to 384 million years old. About 3 mi of the line.
Limestone. Age: Carboniferous to Permian, 252 to 359 million years old. About 3 mi of the line.
Shale, limestone, siltstone. Age: Early Triassic to Late Triassic, 202 to 252 million years old. About 2 mi of the line.
Sandstone, limestone. Age: Jurassic, 145 to 202 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. 7 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 Grover reaches the Pacific Ocean by way of the Salt River, the Snake and the Columbia: about 1,270 river miles.
Lakes on the way: American Falls Reservoir, Palisades Reservoir, Lake Umatilla and Brownlee Reservoir.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Grover; river miles along the main stem, rounded.