The Dillon 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.
Mostly cloudy
Mostly sunny; warmer
Partly cloudy; warmer
Showers likely
Chance of showers; cooler
Chance of showers
Showers likely
64° on Nov. 11, 1980, the hottest reading for this week of the year since 1893. Next is 64° in 1999.
Dillon’s center stands about 9,030 ft above sea level. Within three miles the land runs from 8,690 ft to 11,230 ft, a difference of 2,540 ft: mountain country. The highest named summit within 15 miles is Grays Peak, about 14,210 ft, 12 miles east.
The section below crosses 11 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: Paleoproterozoic, 1.6 to 2.5 billion years old. About 7 mi of the line.
Biotite-gneiss, schist, migmatite. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 4 mi of the line.
Alkali-feldspar-granite, granite. Age: Mesoproterozoic, 1 to 1.6 billion 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. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Gneiss. Age: Paleoproterozoic, 1.6 to 2.5 billion 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. 5 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 Dillon reaches the Gulf of California by way of Dillon Reservoir, the Blue River and the Colorado: about 1,390 river miles.
Lakes on the way: Lake Mead, Lake Powell, Lake Mohave and Lake Havasu.
380 miles of the trip are on the Colorado.
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 Dillon; river miles along the main stem, rounded.
Dillon has a subarctic climate. Summer afternoons average 75° in July; winter nights fall to about 2° in January. A normal year brings about 116 inches of snow; with the rain, that comes to about 15 inches of water.
On November 14 Dillon normally reaches 42° and falls to 12°. The record high is 60°, in 1999; the record low −26°, in 1916. The most rain on this date, 0.45 in, fell in 1983.
Normals 1991–2020 and records since 1893 at Dillon 1 E, here. NOAA, through RCC-ACIS.
