The Anoka 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
Sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy; cooler
Showers likely
Anoka’s center stands about 1,650 ft above sea level. Within three miles the land runs from 1,610 ft to 1,900 ft, a difference of 290 ft: rolling country. The highest named summit within 15 miles is Devils Grave Hill, about 1,940 ft, 15 miles northwest.
Under the town center the state geologic map shows Pierre Shale, from the Late Cretaceous, 66 to 100 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 35×. 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, 66 to 100 million years old. About 12 mi of the line.
Siltstone-mudstone, conglomerate-sandstone. Age: Miocene, 5.3 to 23 million years old. About 4 mi of the line.
Sandstone, limestone, siltstone. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 4 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 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 Anoka reaches the Gulf of America by way of Ponca Creek, the Missouri and the Mississippi: about 2,050 river miles.
Lake on the way: Lewis and Clark Lake.
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 Anoka; river miles along the main stem, rounded.
