The Clark 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.
68° on Nov. 13, 1999, the hottest reading for this week of the year since 1961. Next is 67° in 2001.
Clark’s center stands about 1,280 ft above sea level. Within three miles the land runs from 1,250 ft to 1,340 ft, a difference of 90 ft: gently rolling country.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Slate, graywacke. Age: Paleoproterozoic, 1.6 to 2 billion years old. About 15 mi of the line.
Banded-iron-formation. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 6 mi of the line.
Graywacke, slate. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Graywacke, slate. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 0.7 mi of the line.
Mafic-hypabyssal, diorite, pyroxenite. Age: Mesoproterozoic, 1 to 1.6 billion 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 Clark reaches the Gulf of America by way of Minnewawa Creek, the Sandy and the Mississippi: about 2,110 river miles.
Lakes on the way: Lake Pepin and Aitkin Lake.
1,750 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Clark; river miles along the main stem, rounded.
Clark has a warm-summer humid continental climate. Summer afternoons average 76° in July; winter nights fall to about −3° in January. A normal year brings about 59 inches of snow; with the rain, that comes to about 31 inches of water.
On November 14 Clark normally reaches 36° and falls to 19°. The record high is 60°, in 2016; the record low −1°, in 1965. The most rain on this date, 0.56 in, fell in 2010.
Normals 1991–2020 and records since 1961 at Wright 3 E, 8 miles east-northeast. NOAA, through RCC-ACIS.