The Garrison 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
Mostly sunny; warmer
Partly cloudy
Mostly cloudy
Chance of showers; cooler
Mostly cloudy
Chance of showers
71° on Nov. 13, 1999, the hottest reading for this week of the year since 1948. Next is 70° in 1953.
Garrison’s center stands about 1,920 ft above sea level. Within three miles the land runs from 1,820 ft to 1,990 ft, a difference of 170 ft: gently rolling country. The highest named summit within 15 miles is Blue Hill, about 2,260 ft, 13 miles northwest.
Under the town center the state geologic map shows Sentinel Butte Formation (siltstone, claystone, sandstone), from the Paleocene, 56 to 66 million years old.
The section below crosses 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 45×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone, claystone, sandstone. Age: Paleocene, 56 to 66 million years old. About 21 mi of the line.
Claystone, siltstone. Age: Paleocene, 56 to 66 million years old. About 3 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 Garrison reaches the Gulf of America by way of Lake Sakakawea, the Missouri and the Mississippi: about 2,570 river miles.
Lakes on the way: Lake Oahe, Lake Sakakawea, Lake Sharpe and Lake Francis Case.
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 Garrison; river miles along the main stem, rounded.
Garrison has a dry-winter warm-summer continental climate. Summer afternoons average 81° in July; winter nights fall to about 2° in January. A normal year brings about 43 inches of snow; with the rain, that comes to about 18 inches of water.
On November 14 Garrison normally reaches 38° and falls to 20°. The record high is 64°, in 2001; the record low −7°, in 1959. The most rain on this date, 0.12 in, fell in 1994.
Normals 1991–2020 and records since 1948 at Garrison, here. NOAA, through RCC-ACIS.
