The Donaldson 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.
7.60 inches of rain fell in two days, the most for this week of the year since records began in 1891. The next wettest, 7.26 inches, fell in 1978.
Donaldson’s center stands about 240 ft above sea level. Within three miles the land runs from 210 ft to 410 ft, a difference of 200 ft: rolling country. The highest named summit within 15 miles is Shinn Mountain, about 830 ft, 10 miles north-northwest.
Under the town center the state geologic map shows Alluvium (coarse-detrital, fine-detrital), from the Holocene, less than 12,000 years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 29×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sand, fine-detrital. Age: Early Eocene, 48 to 56 million years old. About 8 mi of the line.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 7 mi of the line.
Black-shale, sandstone, siltstone. Age: Carboniferous, 324 to 359 million years old. About 5 mi of the line.
Sandstone. Age: Silurian, 422 to 445 million years old. About 2 mi of the line.
Sandstone, shale. Age: Carboniferous, 299 to 324 million years old. About 1 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 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. 2 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 Donaldson reaches the Gulf of America by way of the Ouachita, the Black River, the Red River, the Atchafalaya and the Lower Atchafalaya: about 580 river miles.
370 miles of the trip are on the Ouachita.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Donaldson; river miles along the main stem, rounded.
Donaldson has a humid subtropical climate. Summer afternoons average 94° in July; winter nights fall to about 31° in January. About 55 inches of rain fall in a normal year, with about 1 inch of snow.
On November 14 Donaldson normally reaches 66° and falls to 40°. The record high is 84°, in 1999; the record low 20°, in 2019. The most rain on this date, 2.20 in, fell in 1915.
Normals 1991–2020 and records since 1891 at Arkadelphia 2 N, 10 miles southwest. NOAA, through RCC-ACIS.