The St. Marie 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
Mostly cloudy
Showers likely; cooler
Mostly cloudy
Mostly cloudy
75° on Nov. 12, 1999, the hottest reading for this week of the year since 1959. Next is 66° in 2001.
St. Marie’s center stands about 2,720 ft above sea level. Within three miles the land runs from 2,440 ft to 2,770 ft, a difference of 330 ft: rolling country.
Under the town center the state geologic map shows Gravel, from the Late Miocene to Pliocene, 2.6 to 12 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 25×. 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, 72 to 84 million years old. About 17 mi of the line.
Age: Late Miocene to Pliocene, 2.6 to 12 million years old. About 6 mi of the line.
Gravel, sand, silt. Age: Pleistocene to Holocene, less than 1.8 million years old. About 1 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 St. Marie reaches the Gulf of America by way of Porcupine Creek, the Milk River, the Missouri and the Mississippi: about 2,970 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 St. Marie; river miles along the main stem, rounded.
St. Marie has a cold semi-arid climate. Summer afternoons average 85° in July; winter nights fall to about 6° in January. About 12 inches of rain fall in a normal year.
On November 14 St. Marie normally reaches 40° and falls to 21°. The record high is 62°, in 2001; the record low −11°, in 2014. The most rain on this date, 0.10 in, fell in 2021.
Normals 1991–2020 and records since 1959 at St. Marie, here. NOAA, through RCC-ACIS.
