The Blucksberg Mountain 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.
78° on Nov. 12, 1999, the hottest reading for this week of the year since 1902. Next is 77° in 1990.
Blucksberg Mountain’s center stands about 3,820 ft above sea level. Within three miles the land runs from 3,270 ft to 4,640 ft, a difference of 1,370 ft: steep hill country. The highest named summit within 15 miles is Crystal Mountain, about 5,670 ft, 13 miles south-southwest.
Under the town center the state geologic map shows Morrison Formation, Unkpapa Sandstone, Sundance Formation, and Gypsum Springs Formation (sandstone, siltstone, claystone), from the Middle Jurassic to Late Jurassic, 145 to 175 million years old.
The section below crosses 16 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 7×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Hypabyssal-latite, hypabyssal-andesite, hypabyssal-quartz-latite. Age: Paleocene to Eocene, 34 to 66 million years old. About 5 mi of the line.
Shale, siltstone. Age: Early Cretaceous, 100 to 145 million years old. About 3 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 3 mi of the line.
Conglomerate, sandstone, shale. Age: Middle Cambrian to Late Ordovician, 445 to 521 million years old. About 2 mi of the line.
Coarse-detrital, clay. Age: Quaternary, less than 2.6 million years old. About 2 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 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. 10 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 Blucksberg Mountain reaches the Gulf of America by way of Alkali Creek, the Belle Fourche, the Cheyenne, the Missouri and the Mississippi: about 2,500 river miles.
Lakes on the way: Lake Oahe, Lake Sharpe, 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 Blucksberg Mountain; river miles along the main stem, rounded.
Blucksberg Mountain has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 15° in January. A normal year brings about 48 inches of snow; with the rain, that comes to about 21 inches of water.
On November 14 Blucksberg Mountain normally reaches 48° and falls to 25°. The record high is 77°, in 1990; the record low −20°, in 1959. The most rain on this date, 0.59 in, fell in 1956.
Normals 1991–2020 and records since 1902 at Fort Meade, 4 miles north-northwest, 510 ft lower. NOAA, through RCC-ACIS.