The Troy 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.
Troy’s center stands about 750 ft above sea level. Within three miles the land runs from 700 ft to 1,710 ft, a difference of 1,010 ft: steep hill country. The highest named summit within 15 miles is Jay Peak, about 3,810 ft, 6 miles west-northwest.
The section below crosses 13 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 8×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Muscovite-schist, gneiss, quartzite. Age: Neoproterozoic to Early Cambrian, 521 to 1,000 million years old. About 10 mi of the line.
Phyllite, limestone. Age: Silurian to Early Devonian, 394 to 425 million years old. About 5 mi of the line.
Phyllite. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 2 mi of the line.
Quartzite, granofels, phyllite. Age: Cambrian to Early Ordovician, 471 to 542 million years old. About 1 mi of the line.
Metasandstone, metacarbonate, phyllite. Age: Silurian to Early Devonian, 394 to 425 million years old. About 1 mi of the line.
Phyllite. Age: Cambrian, 487 to 542 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. 7 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 Troy reaches the St. Lawrence River by way of the Missisquoi and the Richelieu: about 200 river miles. The St. Lawrence carries it on to the Atlantic.
Lake on the way: Lake Champlain.
80 miles of the trip are on the Richelieu.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Troy; river miles along the main stem, rounded.