The Rancho Grande 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
Mostly sunny; warmer
Mostly sunny
Showers likely
Sunny
Mostly sunny
Mostly sunny
84° on Nov. 14, 2005, the hottest reading for this week of the year since 1906. Next is 81° in 1999.
Rancho Grande’s center stands about 6,350 ft above sea level. Within three miles the land runs from 6,120 ft to 7,420 ft, a difference of 1,300 ft: steep hill country. The highest named summit within 15 miles is Horse Mesa, about 8,760 ft, 7 miles west-northwest.
Under the town center the state geologic map shows Alluvium (unconsolidated), from the Pleistocene to Holocene, less than 0.1 million years old.
The section below crosses 9 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.
Basaltic-andesite, andesite. Age: Late Oligocene to Early Miocene, 22 to 26 million years old. About 5 mi of the line.
Rhyolite. Age: Early Oligocene to Late Oligocene, 24 to 30 million years old. About 5 mi of the line.
Unconsolidated. Age: Pleistocene to Holocene, less than 0.1 million years old. About 4 mi of the line.
Conglomerate-sandstone, volcanic. Age: Late Oligocene to Pleistocene, 0.1 to 28 million years old. About 3 mi of the line.
Clastic, unconsolidated. Age: Late Eocene to Oligocene, 23 to 38 million years old. About 2 mi of the line.
Basalt, andesite. Age: Miocene, 5.3 to 23 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. 3 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 Rancho Grande reaches the Gulf of California by way of the San Francisco, the Gila and the Colorado: about 710 river miles.
460 miles of the trip are on the Gila.
Often dry. About 40% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
Seldom reaches the sea. Dams and canals now take nearly all of the Colorado before its old delta in Mexico.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Rancho Grande; river miles along the main stem, rounded.
Rancho Grande has a humid subtropical climate. Summer afternoons average 92° in July; winter nights fall to about 17° in January. About 17 inches of rain fall in a normal year.
On November 14 Rancho Grande normally reaches 66° and falls to 25°. The record high is 84°, in 2005; the record low 12°, in 2018. The most rain on this date, 1.15 in, fell in 1994.
Normals 1991–2020 and records since 1906 at Reserve Ranger Station, 5 miles east-northeast, 500 ft lower. NOAA, through RCC-ACIS.
