The Somerset 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.
Somerset’s center stands about 6,100 ft above sea level. Within three miles the land runs from 5,930 ft to 8,780 ft, a difference of 2,850 ft: mountain country. The highest named summit within 15 miles is Mount Gunnison, about 12,680 ft, 9 miles south-southeast.
Under the town center the state geologic map shows Mesaverde Fm, undivided (sandstone), from the Late Cretaceous, 66 to 100 million years old.
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 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.
Sandstone. Age: Late Cretaceous, 66 to 100 million years old. About 8 mi of the line.
Claystone. Age: Paleocene to Eocene, 34 to 66 million years old. About 6 mi of the line.
Unconsolidated. Age: Quaternary, less than 2.6 million years old. About 4 mi of the line.
Mafic-hypabyssal, felsic-hypabyssal. Age: Eocene to Miocene, 5.3 to 56 million years old. About 3 mi of the line.
Shale, sandstone. Age: Early Cretaceous to Late Cretaceous, 66 to 145 million years old. About 1 mi of the line.
Unconsolidated. Age: Tertiary to Quaternary, less than 66 million years old. About 0.8 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 Somerset reaches the Gulf of California by way of the North Fork Gunnison, the Gunnison and the Colorado: about 1,260 river miles.
Lakes on the way: Lake Mead, Lake Powell, Lake Mohave and Lake Havasu.
Seldom reaches the sea. Dams and canals now take nearly all of the Colorado before its old delta in Mexico.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Somerset; river miles along the main stem, rounded.