The Lower Mifflin 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.
77° on Nov. 15, 1973, the hottest reading for this week of the year since 1910. Next is 75° in 1993.
Lower Mifflin’s center stands about 840 ft above sea level. Within three miles the land runs from 530 ft to 1,840 ft, a difference of 1,310 ft: steep hill country. The highest named summit within 15 miles is Rising Mountain, about 2,300 ft, 13 miles west-southwest.
Under the town center the state geologic map shows Martinsburg Formation (shale), from the Ordovician, 445 to 487 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 11×. 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: Ordovician, 445 to 487 million years old. About 14 mi of the line.
Quartzite. Age: Silurian, 422 to 445 million years old. About 5 mi of the line.
Shale, sandstone. Age: Silurian, 422 to 445 million years old. About 3 mi of the line.
Sandstone. Age: Ordovician, 445 to 487 million years old. About 1 mi of the line.
Graywacke. Age: Ordovician, 445 to 487 million years old. About 1 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 Lower Mifflin reaches Chesapeake Bay and the Atlantic Ocean by way of Doubling Gap Creek, Conodoguinet Creek and the Susquehanna: about 140 river miles.
Lake on the way: Lake Aldred.
60 miles of the trip are on Conodoguinet Creek.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Lower Mifflin; river miles along the main stem, rounded.
Lower Mifflin has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 22° in January. A normal year brings about 34 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Lower Mifflin normally reaches 54° and falls to 34°. The record high is 73°, in 1989; the record low 14°, in 1986. The most rain on this date, 1.88 in, fell in 1995.
Normals 1991–2020 and records since 1910 at Shippensburg, 14 miles south-southwest, 160 ft lower. NOAA, through RCC-ACIS.