The Forest Ranch 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.
Forest Ranch’s center stands about 2,430 ft above sea level. Within three miles the land runs from 970 ft to 3,210 ft, a difference of 2,240 ft: mountain country. The highest named summit within 15 miles is Table Mountain, about 6,300 ft, 15 miles east-northeast.
Under the town center the state geologic map shows Tertiary pyroclastic and volcanic mudflow deposits, unit 9 (Cascade Range) (andesite), from the Late Oligocene to Pleistocene, 2 to 24 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 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.
Andesite. Age: Late Oligocene to Pleistocene, 2 to 24 million years old. About 10 mi of the line.
Andesite, basalt. Age: Late Oligocene to Pleistocene, 2 to 24 million years old. About 3 mi of the line.
Plutonic, gneiss. Age: Paleoproterozoic to Late Cretaceous, 66 to 2,500 million years old. About 3 mi of the line.
Schist, gneiss. Age: Paleoproterozoic to Cretaceous, 66 to 2,500 million years old. About 3 mi of the line.
Sandstone, conglomerate. Age: Miocene to Pleistocene, less than 23 million years old. About 2 mi of the line.
Sandstone, siltstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 2 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 Forest Ranch reaches San Francisco Bay and the Pacific Ocean by way of Big Chico Creek and the Sacramento: about 210 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Forest Ranch; river miles along the main stem, rounded.