The Butte Valley 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.
85° on Nov. 11, 1930, the hottest reading for this week of the year since 1906. Next is 85° in 1932.
Butte Valley’s center stands about 530 ft above sea level. Within three miles the land runs from 220 ft to 1,110 ft, a difference of 890 ft: hilly country. The highest named summit within 15 miles is Big Bar Mountain, about 4,400 ft, 14 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 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 6×. 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 9 mi of the line.
Coarse-detrital. Age: Pleistocene to Holocene, less than 2.6 million years old. About 8 mi of the line.
Argillite, phyllite. Age: Permian to Jurassic, 145 to 299 million years old. About 5 mi of the line.
Mafic-volcanic. Age: Permian to Jurassic, 145 to 299 million years old. About 2 mi of the line.
Peridotite, serpentinite. Age: Neoproterozoic to Early Jurassic, 175 to 1,000 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 Butte Valley reaches San Francisco Bay and the Pacific Ocean by way of Clear Creek, Dry Creek, Gold Run, Cottonwood Creek, Butte Creek and the Sacramento: about 180 river miles.
140 miles of the trip are on the Sacramento.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Butte Valley; river miles along the main stem, rounded.
Butte Valley has a hot-summer Mediterranean climate. Summer afternoons average 95° in July; winter nights fall to about 36° in January. About 27 inches of rain fall in a normal year.
On November 14 Butte Valley normally reaches 65° and falls to 40°. The record high is 80°, in 2025; the record low 26°, in 1994. The most rain on this date, 1.37 in, fell in 1953.
Normals 1991–2020 and records since 1906 at Chico University Farm, 9 miles west, 340 ft lower. NOAA, through RCC-ACIS.