The Wilsall 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
Mostly sunny
Chance of showers
Chance of showers
Wilsall’s center stands about 5,050 ft above sea level. Within three miles the land runs from 4,940 ft to 5,510 ft, a difference of 570 ft: hilly country. The highest named summit within 15 miles is Sunlight Peak, about 10,020 ft, 15 miles east-northeast.
Under the town center the state geologic map shows Fort Union Formation (sandstone, shale, siltstone), from the Late Cretaceous to Middle Paleocene, 59 to 72 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 5×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, shale, siltstone. Age: Late Cretaceous to Middle Paleocene, 59 to 72 million years old. About 12 mi of the line.
Claystone. Age: Late Cretaceous, 66 to 84 million years old. About 7 mi of the line.
Age: Pleistocene to Holocene, less than 1.8 million years old. About 2 mi of the line.
Sandstone, conglomerate-sandstone. Age: Late Cretaceous, 66 to 72 million years old. About 1 mi of the line.
Volcanic, conglomerate, sandstone. Age: Late Cretaceous, 72 to 84 million years old. About 1 mi of the line.
Gravel, sand, silt. Age: Pleistocene to Holocene, less than 1.8 million years old. About 0.5 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 Wilsall reaches the Gulf of America by way of Flathead Creek, the Shields, the Yellowstone, the Missouri and the Mississippi: about 3,260 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 Wilsall; river miles along the main stem, rounded.
