Where Was the United States 250 Million Years Ago?
April 7, 2026
Today the United States sits between two oceans with no land neighbors except Canada and Mexico. But 250 million years ago, it was fused directly against Africa and Europe in a single massive supercontinent called Pangea. The Atlantic Ocean did not exist.
The United States on Pangea
During the Triassic period, roughly 250 million years ago, the eastern United States was in direct contact with what is now northwestern Africa and the Iberian Peninsula. Rock formations in the Appalachian Mountains of Virginia match rock formations found today in Morocco. They were once the same mountain range, split apart when the Atlantic began to open around 200 million years ago.
Most of the central United States sat near the equator at this time, in a band of hot, semi-arid climate. The vast inland sea that later split North America during the age of dinosaurs did not yet exist. Instead the interior was largely high desert, broken by river systems draining toward the Tethys Sea to the east.
The Climate of the United States 250 Million Years Ago
The interior of Pangea had no moderating ocean influence, which created extreme temperature swings between seasons. The region that is now the American Southwest was one of the driest places on Earth, with sand dunes now preserved as sandstone formations in places like Zion National Park.
Coastal areas in the southeast, facing the Tethys Sea, were warmer and more humid. Life was in recovery from the Permian extinction that had occurred just a few million years earlier, wiping out more than 90 percent of all species. Early dinosaur relatives were beginning to appear across the landscape.
The red sandstone of Zion National Park in Utah is the remains of a vast Triassic desert that existed when the United States was near the equator on Pangea.
The Appalachians Were Once Himalayan in Scale
The gentle, rounded Appalachian Mountains were once among the tallest peaks on Earth. They formed when North America collided with Africa and Europe during the final assembly of Pangea, roughly 300 million years ago. At their peak they may have stood 6,000 to 9,000 meters tall, rivaling the modern Himalayas.
Over the 250 million years since Pangea broke apart, erosion has reduced these mountains to a fraction of their original height. The same ancient rocks appear today in West Africa, confirming that the two continents were once welded together at this seam.
Frequently Asked Questions
Was the eastern United States touching Africa 250 million years ago?
Yes. The eastern seaboard of North America was pressed directly against northwestern Africa. The Appalachian Mountains and the Atlas Mountains of Morocco are remnants of the same collision zone.
Were there dinosaurs in the United States during Pangea?
Not yet. The first dinosaurs appeared around 230 million years ago, a few million years after the classic Pangea configuration. By the time large dinosaurs dominated, Pangea was already breaking apart.
Was the United States near the equator 250 million years ago?
Much of what is now the eastern and central United States was within 30 degrees of the equator, experiencing a hot, semi-arid climate very different from today.