The Sun Prairie 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.
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74° on Nov. 12, 1999, the hottest reading for this week of the year since 1891. Next is 72° in 1990.
Sun Prairie’s center stands about 3,340 ft above sea level. Within three miles the land runs from 3,320 ft to 3,540 ft, a difference of 220 ft: rolling country. The highest named summit within 15 miles is Square Butte, about 4,680 ft, 14 miles west-southwest.
Under the town center the state geologic map shows Alluvium (gravel, sand, silt), from the Pleistocene to Holocene, less than 1.8 million years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 33×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Gravel, sand, silt. Age: Pleistocene to Holocene, less than 1.8 million years old. About 10 mi of the line.
Sandstone. Age: Early Cretaceous, 100 to 125 million years old. About 3 mi of the line.
Sandstone. Age: Early Cretaceous, 113 to 125 million years old. About 3 mi of the line.
Age: Late Miocene to Holocene, less than 7.2 million years old. About 3 mi of the line.
Black-shale, siltstone, sandstone. Age: Early Cretaceous, 100 to 113 million years old. About 2 mi of the line.
Shale. Age: Late Cretaceous, 94 to 100 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. 2 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 Sun Prairie reaches the Gulf of America by way of the Sun River, the Missouri and the Mississippi: about 3,290 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 Sun Prairie; river miles along the main stem, rounded.
Sun Prairie has a cold semi-arid climate. Summer afternoons average 84° in July; winter nights fall to about 15° in January. A normal year brings about 66 inches of snow; with the rain, that comes to about 15 inches of water.
On November 14 Sun Prairie normally reaches 44° and falls to 24°. The record high is 71°, in 1999; the record low −16°, in 2014. The most rain on this date, 0.44 in, fell in 1955.
Normals 1991–2020 and records since 1891 from the Great Falls Area threaded record (Great Falls Airport, 7 miles southeast, 330 ft higher). NOAA, through RCC-ACIS.
