The Aspen 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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70° on Nov. 15, 1999, the hottest reading for this week of the year since 1980. Next is 66° in 1980.
Aspen’s center stands about 7,910 ft above sea level. Within three miles the land runs from 7,760 ft to 10,820 ft, a difference of 3,060 ft: mountain country. The highest named summit within 15 miles is Castle Peak, about 14,160 ft, 13 miles south.
Under the town center the state geologic map shows Gravels and alluviums (gravel, unconsolidated), from the Pleistocene, less than 0.5 million years old.
The section below crosses 9 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.
Arkose, siltstone, conglomerate. Age: Carboniferous to Permian, 252 to 324 million years old. About 10 mi of the line.
Sandstone, shale. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Unconsolidated. Age: Pleistocene, less than 0.5 million years old. About 3 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, limestone, sandstone. Age: Carboniferous, 299 to 324 million years old. About 2 mi of the line.
Gravel, unconsolidated. Age: Pleistocene, less than 0.5 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 3 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 Aspen reaches the Gulf of California by way of Maroon Creek, the Roaring Fork and the Colorado: about 1,300 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 Aspen; river miles along the main stem, rounded.
Aspen has a warm-summer humid continental climate. Summer afternoons average 76° in July; winter nights fall to about 10° in January. A normal year brings about 171 inches of snow; with the rain, that comes to about 24 inches of water.
On November 14 Aspen normally reaches 42° and falls to 20°. The record high is 66°, in 1999; the record low −3°, in 2000. The most rain on this date, 0.69 in, fell in 2009.
Normals 1991–2020 and records since 1980 at Aspen 1 SW, here, 260 ft higher. NOAA, through RCC-ACIS.
