The Preston Lake 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.
Preston Lake’s center stands about 1,050 ft above sea level. Within three miles the land runs from 1,040 ft to 1,080 ft, a difference of 40 ft: nearly flat ground.
Under the town center the state geologic map shows Foliated to gneissic tonalite, granodiorite, and diorite (tonalite, granodiorite, diorite), from the Neoarchean, 2.5 to 2.8 billion 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Tonalite, granodiorite, diorite. Age: Neoarchean, 2.5 to 2.8 billion years old. About 19 mi of the line.
Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 4 mi of the line.
Leucocratic-granitic. Age: Neoarchean, 2.5 to 2.8 billion 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 Preston Lake reaches the Gulf of America by way of Buffalo Creek, the South Fork Crow, the Crow and the Mississippi: about 1,970 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Preston Lake; river miles along the main stem, rounded.