The Ravalli 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.
73° on Nov. 12, 1999, the hottest reading for this week of the year since 1893. Next is 65° in 2009.
Ravalli’s center stands about 2,710 ft above sea level. Within three miles the land runs from 2,640 ft to 4,470 ft, a difference of 1,830 ft: steep hill country. The highest named summit within 15 miles is McDonald Peak, about 9,710 ft, 14 miles east-northeast.
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 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.
Quartzite, argillite, metasiltstone. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 10 mi of the line.
Age: Pleistocene to Holocene, less than 1.8 million years old. About 9 mi of the line.
Sedimentary. Age: Tertiary, 2.6 to 66 million years old. About 2 mi of the line.
Quartzite, metasiltstone, argillite. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 2 mi of the line.
Gravel, sand, silt. Age: Pleistocene to Holocene, less than 1.8 million years old. About 0.3 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 Ravalli reaches the Pacific Ocean by way of the Jocko, the Flathead, the Clark Fork, the Pend Oreille and the Columbia: about 990 river miles.
Lakes on the way: Lake Pend Oreille, Lake Umatilla and Noxon Rapids Reservoir.
460 miles of the trip are on the Columbia.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ravalli; river miles along the main stem, rounded.
Ravalli has a warm-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 18° in January. A normal year brings about 43 inches of snow; with the rain, that comes to about 14 inches of water.
On November 14 Ravalli normally reaches 40° and falls to 25°. The record high is 61°, in 2021; the record low −11°, in 1955. The most rain on this date, 0.34 in, fell in 1927.
Normals 1991–2020 and records since 1893 from the Missoula Area threaded record (Missoula International Airport, 25 miles south, 480 ft higher). NOAA, through RCC-ACIS.