The Onaway 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.
70° on Nov. 11, 1999, the hottest reading for this week of the year since 1915. Next is 69° in 2016.
Onaway’s center stands about 2,630 ft above sea level. Within three miles the land runs from 2,480 ft to 2,910 ft, a difference of 430 ft: hilly country. The highest named summit within 15 miles is Moscow Mountain, about 4,970 ft, 9 miles south.
Under the town center the state geologic map shows Volcanic rocks (basalt, andesite), from the Early Oligocene to Late Oligocene, 26 to 32 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 11×. 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. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 11 mi of the line.
Granodiorite, granite. Age: Early Cretaceous to Late Cretaceous, 67 to 107 million years old. About 8 mi of the line.
Basalt, andesite. Age: Early Oligocene to Late Oligocene, 26 to 32 million years old. About 6 mi of the line.
Mixed-clastic. Age: Early Miocene to Late Miocene, 8 to 17 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 Onaway reaches the Pacific Ocean by way of the Palouse, the Snake and the Columbia: about 510 river miles.
Lake on the way: Lake Umatilla.
210 miles of the trip are on the Columbia.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Onaway; river miles along the main stem, rounded.
Onaway has a dry-summer warm-summer continental climate. Summer afternoons average 84° in August; winter nights fall to about 25° in December. A normal year brings about 41 inches of snow; with the rain, that comes to about 24 inches of water.
On November 14 Onaway normally reaches 45° and falls to 30°. The record high is 60°, in 2025; the record low −12°, in 1955. The most rain on this date, 0.65 in, fell in 1998.
Normals 1991–2020 and records since 1915 at Potlatch 3 NNE, 3 miles northeast, 130 ft higher. NOAA, through RCC-ACIS.