The Morton 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.
Morton’s center stands about 930 ft above sea level. Within three miles the land runs from 890 ft to 2,760 ft, a difference of 1,870 ft: steep hill country. The highest named summit within 15 miles is Black Mountain, about 5,270 ft, 14 miles south-southeast.
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, basaltic-andesite. Age: Late Eocene, 34 to 38 million years old. About 11 mi of the line.
Andesite. Age: Late Eocene to Early Oligocene, 28 to 38 million years old. About 6 mi of the line.
Andesite, basalt. Age: Eocene to Oligocene, 23 to 56 million years old. About 3 mi of the line.
Sand, gravel. Age: Pleistocene, less than 2.6 million years old. About 1 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 1 mi of the line.
Gravel, sand. Age: Pleistocene, less than 2.6 million years old. About 0.9 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 Morton reaches the Pacific Ocean by way of the Tilton, the Cowlitz and the Columbia: about 140 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 Morton; river miles along the main stem, rounded.