The Arrow Rock 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.
Mostly sunny
Partly cloudy; warmer
Sunny
Sunny
Partly cloudy
Partly cloudy
Partly cloudy
0° on Nov. 17, 1959, the coldest reading for this week of the year since 1893. Next is 5° in 1932.
Arrow Rock’s center stands about 720 ft above sea level. Within three miles the land runs from 590 ft to 780 ft, a difference of 190 ft: gently rolling country.
Under the town center the state geologic map shows Osagean Series (limestone), from the Carboniferous, 324 to 359 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone. Age: Carboniferous, 324 to 359 million years old. About 11 mi of the line.
Limestone, shale. Age: Carboniferous, 299 to 324 million years old. About 5 mi of the line.
Shale, sandstone, siltstone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Clay, silt, sand. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
Shale, siltstone, mudstone. Age: Carboniferous, 299 to 324 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.
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 Arrow Rock reaches the Gulf of America by way of the Missouri and the Mississippi: about 1,370 river miles.
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 Arrow Rock; river miles along the main stem, rounded.
Arrow Rock has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 19° in January. A normal year brings about 8 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Arrow Rock normally reaches 54° and falls to 34°. The record high is 80°, in 1964; the record low 6°, in 1940. The most rain on this date, 1.33 in, fell in 1985.
Normals 1991–2020 and records since 1893 at Marshall, 15 miles west-northwest. NOAA, through RCC-ACIS.
