The Mountain City 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.
Partly cloudy
Partly cloudy; warmer
Showers likely; cooler
Showers likely; cooler
Showers likely
Chance of showers
Chance of showers
−16° on Nov. 17, 2000, the coldest reading for this week of the year since 1982. Next is −11° in 2020.
Mountain City’s center stands about 5,650 ft above sea level. Within three miles the land runs from 5,590 ft to 6,910 ft, a difference of 1,320 ft: steep hill country. The highest named summit within 15 miles is Porter Peak, about 9,260 ft, 14 miles southwest.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 7×. 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, dacite. Age: Middle Eocene to Early Oligocene, 28 to 48 million years old. About 9 mi of the line.
Granodiorite, granite. Age: Cretaceous, 66 to 145 million years old. About 7 mi of the line.
Clastic, volcanic. Age: Late Devonian to Permian, 252 to 384 million years old. About 3 mi of the line.
Rhyolite, hypabyssal-quartz-latite, dacite. Age: Miocene, 5.3 to 23 million years old. About 2 mi of the line.
Coarse-detrital. Age: Pliocene to Holocene, less than 5.3 million years old. About 2 mi of the line.
Limestone, basalt, chert. Age: Carboniferous, 324 to 359 million years old. About 0.6 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 3 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 Mountain City reaches the Pacific Ocean by way of the Owyhee, the Snake and the Columbia: about 1,010 river miles.
Lakes on the way: Lake Umatilla, Brownlee Reservoir, Lake Owyhee and Hells Canyon Reservoir.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mountain City; river miles along the main stem, rounded.
Mountain City has a dry-summer warm-summer continental climate. Summer afternoons average 85° in July; winter nights fall to about 5° in January. A normal year brings about 117 inches of snow; with the rain, that comes to about 13 inches of water.
On November 14 Mountain City normally reaches 45° and falls to 17°. The record high is 67°, in 1999; the record low −3°, in 1994. The most rain on this date, 0.61 in, fell in 1987.
Normals 1991–2020 and records since 1982 at Wild Horse Reservoir, 16 miles south-southeast, 570 ft higher. NOAA, through RCC-ACIS.
