The Heart Butte 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
Partly cloudy
Partly cloudy
Chance of showers
Partly cloudy
Chance of showers
Partly cloudy
Heart Butte’s center stands about 4,440 ft above sea level. Within three miles the land runs from 4,300 ft to 5,090 ft, a difference of 790 ft: hilly country. The highest named summit within 15 miles is Mount Field, about 8,500 ft, 14 miles south-southwest.
Under the town center the state geologic map shows Glacial deposit (unconsolidated), from the Pleistocene to Holocene, less than 1.8 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.
Unconsolidated. Age: Pleistocene to Holocene, less than 1.8 million years old. About 16 mi of the line.
Limestone, dolostone, shale. Age: Late Devonian to Early Mississippian, 347 to 374 million years old. About 3 mi of the line.
Shale, dolostone, limestone. Age: Late Cretaceous, 84 to 100 million years old. About 2 mi of the line.
Dolostone, limestone, shale. Age: Middle Cambrian to Cambrian, 487 to 521 million years old. About 2 mi of the line.
Limestone, dolostone, black-shale. Age: Early Mississippian to Middle Mississippian, 331 to 359 million years old. About 1.0 mi of the line.
Mudstone, siltstone, sandstone. Age: Early Cretaceous, 100 to 133 million years old. About 0.4 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 Heart Butte reaches the Gulf of America by way of Whitetail Creek, Badger Creek, the Two Medicine, the Marias, the Missouri and the Mississippi: about 3,440 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 Heart Butte; river miles along the main stem, rounded.
