The Fort Shaw 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
Partly cloudy
Showers likely; cooler
Partly cloudy
Chance of showers
Chance of showers
73° on Nov. 12, 1999, the hottest reading for this week of the year since 1912. Next is 72° in 1990.
Fort Shaw’s center stands about 3,510 ft above sea level. Within three miles the land runs from 3,430 ft to 4,350 ft, a difference of 920 ft: steep hill country. The highest named summit within 15 miles is Lionhead Butte, about 4,980 ft, 14 miles south-southwest.
Under the town center the state geologic map shows Ferdig Member of Marias River Formation (shale), from the Late Cretaceous, 87 to 94 million years old.
The section below crosses 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 17×. 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, 87 to 94 million years old. About 6 mi of the line.
Age: Late Miocene to Holocene, less than 7.2 million years old. About 6 mi of the line.
Shale, limestone, dolostone. Age: Late Cretaceous, 84 to 90 million years old. About 4 mi of the line.
Syenitic. Age: Cretaceous, 66 to 145 million years old. About 2 mi of the line.
Age: Pleistocene to Holocene, less than 1.8 million years old. About 2 mi of the line.
Sandstone, siltstone, mudstone. Age: Late Cretaceous, 66 to 84 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. 4 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 Fort Shaw reaches the Gulf of America by way of Adobe Creek, the Sun River, the Missouri and the Mississippi: about 3,310 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 Fort Shaw; river miles along the main stem, rounded.
Fort Shaw has a cold semi-arid climate. Summer afternoons average 83° in July; winter nights fall to about 13° in January. About 13 inches of rain fall in a normal year.
On November 14 Fort Shaw normally reaches 45° and falls to 22°. The record high is 72°, in 1999; the record low −17°, in 2014. The most rain on this date, 0.17 in, fell in 1988.
Normals 1991–2020 and records since 1912 at Sun River 4 S, 4 miles east-southeast. NOAA, through RCC-ACIS.
