The Green Isle 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.
74° on Nov. 16, 2001, the hottest reading for this week of the year since 1956. Next is 72° in 1999.
Green Isle’s center stands about 990 ft above sea level. Within three miles the land runs from 980 ft to 1,020 ft, a difference of 40 ft: nearly flat ground.
Under the town center the state geologic map shows Upper Cambrian (sandstone, siltstone, shale), from the Cambrian, 487 to 497 million years old.
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 58×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, siltstone, shale. Age: Cambrian, 487 to 497 million years old. About 11 mi of the line.
Claystone, siltstone, sandstone. Age: Early Cretaceous, 100 to 113 million years old. About 8 mi of the line.
Dolostone, sandstone. Age: Early Ordovician, 471 to 487 million years old. About 4 mi of the line.
Sandstone, siltstone, shale. Age: Middle Cambrian to Cambrian, 487 to 521 million years old. About 0.3 mi of the line.
Sandstone, siltstone. Age: Mesoproterozoic, 1 to 1.2 billion years old. About 0.2 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 Green Isle reaches the Gulf of America by way of Bevens Creek, the Minnesota and the Mississippi: about 1,900 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Green Isle; river miles along the main stem, rounded.
Green Isle has a cold desert climate. Summer afternoons average 82° in July; winter nights fall to about 6° in January. Barely 0.0 inches of rain fall in a normal year.
On November 14 Green Isle normally reaches 41° and falls to 26°. The record high is 69°, in 1990; the record low −5°, in 1959. The most rain on this date, 0.34 in, fell in 2024.
Normals 1991–2020 and records since 1956 at Gaylord, 14 miles southwest. NOAA, through RCC-ACIS.