The Custer 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.
79° on Nov. 14, 1999, the hottest reading for this week of the year since 1887. Next is 74° in 1953.
Custer’s center stands about 1,530 ft above sea level. Within three miles the land runs from 1,430 ft to 1,580 ft, a difference of 150 ft: gently rolling country. The highest named summit within 15 miles is Poverty Hill, about 1,730 ft, 10 miles south.
Under the town center the state geologic map shows Undifferentiated (conglomerate, sandstone, mudstone), from the Late Cretaceous, 72 to 100 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 31×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million years old. About 15 mi of the line.
Quartzite, mudstone. Age: Paleoproterozoic, 1.6 to 2 billion years old. About 4 mi of the line.
Orthogneiss, migmatite. Age: Paleoarchean to Mesoarchean, 2.8 to 3.6 billion years old. About 3 mi of the line.
Granitic. Age: Neoarchean, 2.5 to 2.8 billion 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.
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 Custer reaches the Gulf of America by way of the Des Moines and the Mississippi: about 1,870 river miles.
Lakes on the way: Roberts Creek, Big Creek Pounding Area and Armstrong Slough.
1,330 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Custer; river miles along the main stem, rounded.
Custer has a hot-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 5° in January. A normal year brings about 49 inches of snow; with the rain, that comes to about 29 inches of water.
On November 14 Custer normally reaches 42° and falls to 25°. The record high is 79°, in 1999; the record low −10°, in 1959. The most rain on this date, 0.38 in, fell in 1983.
Normals 1991–2020 and records since 1887 at Tracy, 8 miles east, 130 ft lower. NOAA, through RCC-ACIS.