The Allen 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.
Partly cloudy
Mostly sunny; warmer
Mostly sunny
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Partly cloudy
Showers likely
78° on Nov. 17, 2017, the hottest reading for this week of the year since 1956. Next is 77° in 2016.
Allen’s center stands about 3,300 ft above sea level. Within three miles the land runs from 3,200 ft to 3,470 ft, a difference of 270 ft: rolling country.
Under the town center the state geologic map shows Arikaree Group (siltstone, sandstone), from the Oligocene to Miocene, 5.3 to 34 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 27×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone, sandstone. Age: Oligocene to Miocene, 5.3 to 34 million years old. About 17 mi of the line.
Silt, sand. Age: Quaternary, less than 2.6 million years old. About 6 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 1 mi of the line.
Sandstone, limestone, siltstone. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 0.3 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 Allen reaches the Gulf of America by way of Bear-in-the-Lodge Creek, the White River, the Missouri and the Mississippi: about 2,470 river miles.
Lakes on the way: Lake Francis Case and Lewis and Clark Lake.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Allen; river miles along the main stem, rounded.
Allen has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 11° in January. About 22 inches of rain fall in a normal year.
Normals 1991–2020 and records since 1956 at Kyle 2 E, 16 miles northwest, 340 ft lower. NOAA, through RCC-ACIS.
