The Guilford 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.
Guilford Lake’s center stands about 1,160 ft above sea level. Within three miles the land runs from 1,120 ft to 1,360 ft, a difference of 240 ft: rolling country. The highest named summit within 15 miles is Round Knob, about 1,440 ft, 14 miles southeast.
Under the town center the state geologic map shows Allegheny and Pottsville Groups, Undivided (shale, siltstone), from the Carboniferous, 299 to 324 million years old.
The section below crosses 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 46×. 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, siltstone. Age: Carboniferous, 299 to 324 million years old. About 14 mi of the line.
Shale, siltstone, mudstone. Age: Carboniferous, 299 to 324 million years old. About 10 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 Guilford Lake reaches the Gulf of America by way of West Fork Little Beaver Creek, Little Beaver Creek, the Ohio and the Mississippi: about 1,950 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Guilford Lake; river miles along the main stem, rounded.