The Hyampom 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.
Hyampom’s center stands about 1,300 ft above sea level. Within three miles the land runs from 1,240 ft to 3,370 ft, a difference of 2,130 ft: mountain country. The highest named summit within 15 miles is Hayfork Bally, about 6,250 ft, 13 miles east-northeast.
Under the town center the state geologic map shows Oligocene nonmarine rocks, unit 1 (Northern California) (sandstone), from the Oligocene to Miocene, 5.3 to 34 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 4×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Melange. Age: Devonian to Jurassic, 145 to 422 million years old. About 8 mi of the line.
Sandstone, mudstone. Age: Jurassic to Cretaceous, 66 to 202 million years old. About 5 mi of the line.
Diorite. Age: Jurassic to Early Cretaceous, 100 to 202 million years old. About 3 mi of the line.
Mica-schist. Age: Early Cretaceous, 110 to 143 million years old. About 3 mi of the line.
Sandstone. Age: Oligocene to Miocene, 5.3 to 34 million years old. About 3 mi of the line.
Slate, graywacke. Age: Triassic to Late Jurassic, 145 to 252 million 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 Hyampom reaches the Pacific Ocean by way of the South Fork Trinity, the Trinity and the Klamath: about 100 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Hyampom; river miles along the main stem, rounded.