The Lead 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.
Partly cloudy
Sunny; warmer
Mostly sunny
Partly cloudy
Mostly sunny; cooler
Partly cloudy
Chance of showers
73° on Nov. 12, 1999, the hottest reading for this week of the year since 1909. Next is 69° in 1953.
Lead’s center stands about 5,230 ft above sea level. Within three miles the land runs from 4,630 ft to 6,060 ft, a difference of 1,430 ft: steep hill country. The highest named summit within 15 miles is Terry Peak, about 7,040 ft, 4 miles west-southwest.
The section below crosses 13 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 6×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone, dolostone. Age: Late Devonian to Early Mississippian, 347 to 384 million years old. About 7 mi of the line.
Claystone, siltstone, sandstone. Age: Eocene to Oligocene, 23 to 56 million years old. About 4 mi of the line.
Conglomerate, sandstone, shale. Age: Middle Cambrian to Late Ordovician, 445 to 521 million years old. About 3 mi of the line.
Phyllite, slate, biotite-schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Quartzite, schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Hypabyssal-trachyte, hypabyssal-quartz-trachyte, hypabyssal-rhyolite. Age: Paleocene to Eocene, 34 to 66 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. 7 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 Lead reaches the Gulf of America by way of Whitewood Creek, the Belle Fourche, the Cheyenne, the Missouri and the Mississippi: about 2,550 river miles.
Lakes on the way: Lake Oahe, Lake Sharpe, Lake Francis Case and Lewis and Clark Lake.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Lead; river miles along the main stem, rounded.
Lead has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 18° in January. A normal year brings about 184 inches of snow; with the rain, that comes to about 32 inches of water.
On November 14 Lead normally reaches 47° and falls to 26°. The record high is 69°, in 1990; the record low −6°, in 1959. The most rain on this date, 1.91 in, fell in 1944.
Normals 1991–2020 and records since 1909 at Lead, here, 120 ft lower. NOAA, through RCC-ACIS.
