The 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.
13° on Nov. 11, 2017, the coldest reading for this week of the year since 1948. Next is 15° in 1986.
Mifflin’s center stands about 1,550 ft above sea level. Within three miles the land runs from 670 ft to 1,820 ft, a difference of 1,150 ft: steep hill country. The highest named summit within 15 miles is Laurel Mountain, about 2,350 ft, 14 miles north-northeast.
The section below crosses 16 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 12×. 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: Late Devonian, 359 to 384 million years old. About 7 mi of the line.
Sandstone, siltstone. Age: Devonian to Carboniferous, 324 to 422 million years old. About 3 mi of the line.
Sandstone. Age: Carboniferous, 324 to 359 million years old. About 3 mi of the line.
Shale, siltstone, sandstone. Age: Carboniferous, 324 to 359 million years old. About 2 mi of the line.
Sandstone, conglomerate. Age: Carboniferous, 299 to 324 million years old. About 2 mi of the line.
Limestone, dolostone. Age: Ordovician, 445 to 487 million years old. About 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. 10 smaller units 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 Mifflin reaches Chesapeake Bay and the Atlantic Ocean by way of Second Fork Larrys Creek, Larrys Creek, the West Branch Susquehanna and the Susquehanna: about 190 river miles.
Lake on the way: Lake Aldred.
85 miles of the trip are on the Susquehanna.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mifflin; river miles along the main stem, rounded.
Mifflin has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 18° in January. A normal year brings about 30 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Mifflin normally reaches 51° and falls to 31°. The record high is 64°, in 2011; the record low 20°, in 2004. The most rain on this date, 0.57 in, fell in 1997.
Normals 1991–2020 and records since 1948 at Lock Haven Sewage Plant, 15 miles southwest, 980 ft lower. NOAA, through RCC-ACIS.