The Ocheyedan 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
Mostly sunny
Partly cloudy
Partly cloudy
Mostly sunny
Showers likely
76° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 74° in 1912.
Ocheyedan’s center stands about 1,570 ft above sea level. Within three miles the land runs from 1,460 ft to 1,590 ft, a difference of 130 ft: gently rolling country.
Under the town center the state geologic map shows Fort Benton Group (shale), from the Late Cretaceous, 90 to 100 million years old.
The section below crosses 3 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.
Shale. Age: Late Cretaceous, 90 to 100 million years old. About 11 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 9 mi of the line.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million years old. About 4 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 Ocheyedan reaches the Gulf of America by way of the Ocheyedan, the Little Sioux, the Missouri and the Mississippi: about 2,040 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 Ocheyedan; river miles along the main stem, rounded.
Ocheyedan has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 5° in January. A normal year brings about 42 inches of snow; with the rain, that comes to about 30 inches of water.
On November 14 Ocheyedan normally reaches 43° and falls to 23°. The record high is 76°, in 1999; the record low −20°, in 1959. The most rain on this date, 1.62 in, fell in 1909.
Normals 1991–2020 and records since 1893 at Sibley, 11 miles west. NOAA, through RCC-ACIS.
