The Round Rock 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.
Round Rock’s center stands about 5,340 ft above sea level. Within three miles the land runs from 5,250 ft to 5,720 ft, a difference of 470 ft: hilly country. The highest named summit within 15 miles is White Ash Peak, about 8,840 ft, 11 miles east-northeast.
Under the town center the state geologic map shows Chinle Formation (mudstone), from the Late Triassic, 210 to 230 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 5×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Mudstone. Age: Late Triassic, 210 to 230 million years old. About 18 mi of the line.
Sandstone. Age: Late Triassic to Early Jurassic, 180 to 210 million years old. About 4 mi of the line.
Conglomerate, sandstone. Age: Early Paleocene to Early Oligocene, 30 to 65 million years old. About 1 mi of the line.
Silt, clay. Age: Holocene, less than 10,000 years old. About 0.7 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 Round Rock reaches the Gulf of California by way of Lukachukai Creek, Chinle Wash, Chinle Creek, the San Juan and the Colorado: about 1,080 river miles.
Lakes on the way: Lake Mead, Lake Powell, Lake Mohave and Lake Havasu.
290 miles of the trip are on the Colorado.
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 Round Rock; river miles along the main stem, rounded.