The Tonalea 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.
Mostly sunny
Partly cloudy
Partly cloudy
Showers likely
Partly cloudy
Chance of showers
Chance of showers
Tonalea’s center stands about 5,650 ft above sea level. Within three miles the land runs from 5,410 ft to 5,860 ft, a difference of 450 ft: hilly country. The highest named summit within 15 miles is Yellow Butte, about 6,890 ft, 12 miles east-northeast.
Under the town center the state geologic map shows Glen Canyon Group (sandstone), from the Late Triassic to Early Jurassic, 180 to 210 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 13×. 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. Age: Early Jurassic to Late Jurassic, 160 to 180 million years old. About 14 mi of the line.
Sandstone. Age: Late Triassic to Early Jurassic, 180 to 210 million years old. About 9 mi of the line.
Sandstone, shale. Age: Late Cretaceous, 88 to 97 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.
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 Tonalea reaches the Gulf of California by way of the Little Colorado and the Colorado: about 840 river miles.
Lakes on the way: Lake Mead, 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 Tonalea; river miles along the main stem, rounded.
