The Snoqualmie Pass 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.
Chance of showers
Showers likely
Mostly sunny
Mostly sunny
Chance of showers
Mostly cloudy
Partly cloudy
12° on Nov. 14, 2014, the coldest reading for this week of the year since 1905. Next is 21° in 2012.
Snoqualmie Pass’s center stands about 2,770 ft above sea level. Within three miles the land runs from 2,190 ft to 5,260 ft, a difference of 3,070 ft: mountain country. The highest named summit within 15 miles is Mount Hinman, about 7,430 ft, 15 miles northeast.
Under the town center the state geologic map shows Paleocene-Cretaceous nonmarine rocks (arkose), from the Late Cretaceous to Eocene, 34 to 100 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 5×. 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, basalt. Age: Eocene to Oligocene, 23 to 56 million years old. About 7 mi of the line.
Arkose. Age: Late Cretaceous to Eocene, 34 to 100 million years old. About 5 mi of the line.
Arkose. Age: Eocene to Early Oligocene, 28 to 56 million years old. About 4 mi of the line.
Granodiorite, granite. Age: Early Paleocene to Middle Miocene, 12 to 66 million years old. About 4 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
Phyllite. Age: Jurassic to Early Cretaceous, 100 to 202 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.
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 Snoqualmie Pass reaches the Pacific Ocean by way of Tunnel Creek, Coal Creek, the Yakima and the Columbia: about 550 river miles.
Lake on the way: Lake Umatilla.
220 miles of the trip are on the Yakima.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Snoqualmie Pass; river miles along the main stem, rounded.
Snoqualmie Pass has a dry-summer warm-summer continental climate. Summer afternoons average 76° in July; winter nights fall to about 25° in January. About 50 inches of rain fall in a normal year.
Normals 1991–2020 and records since 1905 at Easton, 14 miles southeast, 600 ft lower. NOAA, through RCC-ACIS.
