The Gallagher 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 cloudy
Partly cloudy
Partly cloudy
Sunny
Sunny
Partly cloudy
Mostly sunny
Gallagher’s center stands about 1,690 ft above sea level. Within three miles the land runs from 1,300 ft to 2,010 ft, a difference of 710 ft: hilly country. The highest named summit within 15 miles is Riansares Mountain, about 2,340 ft, 14 miles south-southeast.
Under the town center the state geologic map shows Burgoon Sandstone, from the Carboniferous, 324 to 359 million years old.
The section below crosses 11 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 12×. 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, siltstone. Age: Devonian to Carboniferous, 324 to 422 million years old. About 6 mi of the line.
Sandstone. Age: Carboniferous, 324 to 359 million years old. About 6 mi of the line.
Shale, siltstone, sandstone. Age: Carboniferous, 324 to 359 million years old. About 5 mi of the line.
Sandstone, siltstone, mudstone. Age: Late Devonian, 359 to 384 million years old. About 3 mi of the line.
Limestone, shale, mudstone. Age: Silurian to Devonian, 359 to 445 million years old. About 1 mi of the line.
Sandstone. Age: Ordovician, 445 to 487 million years old. About 0.9 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 5 smaller units along the line are not listed.
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 Gallagher reaches Chesapeake Bay and the Atlantic Ocean by way of Staver Run, Lick Run, the West Branch Susquehanna and the Susquehanna: about 220 river miles.
Lake on the way: Lake Aldred.
85 miles of the trip are on the Susquehanna.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Gallagher; river miles along the main stem, rounded.
