The Johnson Siding 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
Sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy; cooler
Partly cloudy
Chance of showers
74° on Nov. 13, 1999, the hottest reading for this week of the year since 1951. Next is 72° in 1990.
Johnson Siding’s center stands about 4,310 ft above sea level. Within three miles the land runs from 4,150 ft to 5,160 ft, a difference of 1,010 ft: steep hill country. The highest named summit within 15 miles is Castle Peak, about 6,330 ft, 14 miles west.
Under the town center the state geologic map shows Metaquartzite (quartzite, schist), from the Paleoproterozoic, 1.6 to 2.5 billion years old.
The section below crosses 19 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.
Sandstone, siltstone, shale. Age: Late Pennsylvanian to Permian, 273 to 307 million years old. About 3 mi of the line.
Biotite-schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 3 mi of the line.
Mica-schist, quartzite. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 3 mi of the line.
Phyllite, schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Limestone, dolostone. Age: Late Devonian to Early Mississippian, 347 to 384 million years old. About 2 mi of the line.
Quartzite, schist. Age: Paleoproterozoic, 1.6 to 2.5 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. 13 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 Johnson Siding reaches the Gulf of America by way of Rapid Creek, the Cheyenne, the Missouri and the Mississippi: about 2,540 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 Johnson Siding; river miles along the main stem, rounded.
Johnson Siding has a dry-winter warm-summer continental climate. Summer afternoons average 79° in July; winter nights fall to about 11° in February. A normal year brings about 61 inches of snow; with the rain, that comes to about 22 inches of water.
On November 14 Johnson Siding normally reaches 45° and falls to 21°. The record high is 70°, in 1999; the record low −21°, in 1959. The most rain on this date, 0.40 in, fell in 1956.
Normals 1991–2020 and records since 1951 at Pactola Dam, 3 miles southwest, 410 ft higher. NOAA, through RCC-ACIS.
