The Lake Morton-Berrydale 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.
3.80 inches of rain fell in two days, the most for this week of the year since records began in 1945. The next wettest, 3.18 inches, fell in 2015.
Lake Morton-Berrydale’s center stands about 460 ft above sea level. Within three miles the land runs from 230 ft to 600 ft, a difference of 370 ft: rolling country. The highest named summit within 15 miles is Tiger Mountain, about 3,000 ft, 13 miles northeast.
Under the town center the state geologic map shows Younger glacial drift (fine-detrital, coarse-detrital), from the Pleistocene, less than 2.6 million years old.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 6×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 9 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 6 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 5 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
Sandstone. Age: Early Eocene to Middle Eocene, 38 to 56 million years old. About 1 mi of the line.
Andesite. Age: Oligocene to Middle Miocene, 12 to 34 million years old. About 0.8 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit along the line are not listed.
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 Lake Morton-Berrydale reaches Puget Sound and the Pacific Ocean by way of Covington Creek, Big Soos Creek, the Green River, the Duwamish and the Duwamish Waterway: about 40 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Lake Morton-Berrydale; river miles along the main stem, rounded.
Lake Morton-Berrydale has a warm-summer Mediterranean climate. Summer afternoons average 78° in August; winter nights fall to about 37° in December. A normal year brings about 6 inches of snow; with the rain, that comes to about 39 inches of water.
On November 14 Lake Morton-Berrydale normally reaches 52° and falls to 41°. The record high is 65°, in 1995; the record low 9°, in 1955. The most rain on this date, 2.61 in, fell in 2001.
Normals 1991–2020 and records since 1945 from the Seattle Tacoma Area threaded record (Seattle Tacoma Airport, 13 miles northwest). NOAA, through RCC-ACIS.