The Powder Horn 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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81° on Nov. 12, 1999, the hottest reading for this week of the year since 1907. Next is 75° in 2025.
Powder Horn’s center stands about 4,040 ft above sea level. Within three miles the land runs from 3,890 ft to 4,450 ft, a difference of 560 ft: hilly country. The highest named summit within 15 miles is Little Goose Peak, about 9,310 ft, 11 miles south-southwest.
Under the town center the state geologic map shows Alluvium and Colluvium (clay, silt, sand), from the Pleistocene to Holocene, less than 2.6 million years old.
The section below crosses 8 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.
Clay, silt, sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 10 mi of the line.
Mudstone, sandstone. Age: Eocene, 34 to 56 million years old. About 5 mi of the line.
Gneiss, quartz-diorite, quartz-monzonite. Age: Archean. About 4 mi of the line.
Conglomerate. Age: Eocene, 34 to 56 million years old. About 2 mi of the line.
Shale, siltstone. Age: Late Cretaceous, 78 to 83 million years old. About 1 mi of the line.
Limestone, dolostone. Age: Late Devonian to Carboniferous, 324 to 384 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. 2 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 Powder Horn reaches the Gulf of America by way of Little Goose Creek, Goose Creek, the Tongue River, the Yellowstone, the Missouri and the Mississippi: about 3,190 river miles.
Lakes on the way: Lake Oahe, Lake Sakakawea, Lake Sharpe and Lake Francis Case.
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 Powder Horn; river miles along the main stem, rounded.
Powder Horn has a warm-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 12° in January. About 15 inches of rain fall in a normal year.
On November 14 Powder Horn normally reaches 47° and falls to 20°. The record high is 75°, in 2025; the record low −19°, in 1959. The most rain on this date, 0.54 in, fell in 1964.
Normals 1991–2020 and records since 1907 from the Sheridan Area threaded record (Sheridan Airport, 5 miles north). NOAA, through RCC-ACIS.
