The Pony 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
Partly cloudy
Chance of showers
Showers likely; cooler
Partly cloudy
Chance of showers
Chance of showers
71° on Nov. 12, 1999, the hottest reading for this week of the year since 1907. Next is 68° in 2016.
Pony’s center stands about 5,510 ft above sea level. Within three miles the land runs from 5,170 ft to 7,500 ft, a difference of 2,330 ft: mountain country. The highest named summit within 15 miles is Hollowtop Mountain, about 10,590 ft, 6 miles west-southwest.
The section below crosses 11 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 3×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Granitic. Age: Cretaceous, 66 to 145 million years old. About 9 mi of the line.
Gneiss. Age: Archean. About 6 mi of the line.
Siltstone, sedimentary-breccia, conglomerate. Age: Early Eocene to Early Miocene, 16 to 56 million years old. About 3 mi of the line.
Conglomerate, sandstone, siltstone. Age: Early Miocene to Pliocene, 2.6 to 20 million years old. About 2 mi of the line.
Limestone, dolostone, black-shale. Age: Early Mississippian to Middle Mississippian, 331 to 359 million years old. About 1 mi of the line.
Dolostone, limestone, sandstone. Age: Late Mississippian to Permian, 252 to 331 million years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 5 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 Pony reaches the Gulf of America by way of North Willow Creek, Willow Creek, the Jefferson, the Missouri and the Mississippi: about 3,510 river miles.
Lakes on the way: Lake Oahe, Lake Sakakawea, Lake Fort Peck and Lake Sharpe.
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 Pony; river miles along the main stem, rounded.
Pony has a warm-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 24° in January. A normal year brings about 52 inches of snow; with the rain, that comes to about 18 inches of water.
On November 14 Pony normally reaches 47° and falls to 31°. The record high is 69°, in 1999; the record low −7°, in 1955. The most rain on this date, 0.36 in, fell in 2017.
Normals 1991–2020 and records since 1907 at Norris Madison Power House, 17 miles southeast, 760 ft lower. NOAA, through RCC-ACIS.
