The Ryderwood 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.
3.49 inches of rain fell in two days, the most for this week of the year since records began in 1925. The next wettest, 3.36 inches, fell in 2021.
Ryderwood’s center stands about 270 ft above sea level. Within three miles the land runs from 190 ft to 1,530 ft, a difference of 1,340 ft: steep hill country. The highest named summit within 15 miles is Boistfort Peak, about 3,100 ft, 11 miles northwest.
Under the town center the state geologic map shows Alluvium (silt, sand), from the Holocene, less than 12,000 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 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.
Basalt. Age: Early Paleocene to Middle Eocene, 40 to 64 million years old. About 9 mi of the line.
Sandstone. Age: Early Eocene to Middle Eocene, 38 to 56 million years old. About 7 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 3 mi of the line.
Gravel, sand. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Siltstone, sandstone. Age: Middle Eocene to Late Eocene, 34 to 48 million years old. About 2 mi of the line.
Basalt. Age: Late Oligocene to Early Pliocene, 3.6 to 28 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 Ryderwood reaches the Pacific Ocean by way of Becker Creek, Stillwater Creek, Olequa Creek, the Cowlitz and the Columbia: about 100 river miles.
65 miles of the trip are on the Columbia.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ryderwood; river miles along the main stem, rounded.
Ryderwood has a warm-summer Mediterranean climate. Summer afternoons average 80° in August; winter nights fall to about 35° in January. About 48 inches of rain fall in a normal year.
On November 14 Ryderwood normally reaches 53° and falls to 39°. The record high is 68°, in 1999; the record low 12°, in 1955. The most rain on this date, 1.65 in, fell in 2001.
Normals 1991–2020 and records since 1925 at Longview, 17 miles south, 260 ft lower. NOAA, through RCC-ACIS.