The Mammoth 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.
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75° on Nov. 11, 2002, the hottest reading for this week of the year since 1943. Next is 75° in 2020.
Mammoth’s center stands about 1,130 ft above sea level. Within three miles the land runs from 990 ft to 2,030 ft, a difference of 1,040 ft: steep hill country. The highest named summit within 15 miles is Bald Knob, about 2,960 ft, 15 miles east-southeast.
Under the town center the state geologic map shows Casselman Formation (shale, clastic), from the Carboniferous, 299 to 324 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 13×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale. Age: Carboniferous, 299 to 324 million years old. About 9 mi of the line.
Shale, clastic. Age: Carboniferous, 299 to 324 million years old. About 6 mi of the line.
Limestone, shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 5 mi of the line.
Sandstone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Sandstone, conglomerate. Age: Carboniferous, 299 to 324 million years old. About 0.4 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 Mammoth reaches the Gulf of America by way of Welty Run, Sewickley Creek, the Youghiogheny, the Monongahela, the Ohio and the Mississippi: about 2,000 river miles.
970 miles of the trip are on the Ohio.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mammoth; river miles along the main stem, rounded.
Mammoth has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 19° in January. About 50 inches of rain fall in a normal year.
On November 14 Mammoth normally reaches 51° and falls to 32°. The record high is 69°, in 1989; the record low 8°, in 1986. The most rain on this date, 0.77 in, fell in 1961.
Normals 1991–2020 and records since 1943 at Donegal 2 NW, 6 miles south-southeast, 670 ft higher. NOAA, through RCC-ACIS.
