North America
Tucked between the Appalachian Mountains and the Atlantic Ocean, the Chesapeake Bay forms part of the coastal plain of the Eastern United States. Both the Delaware and Susquehanna rivers empty into the bay, irrigating thousands of acres of cropland and protected wetlands. Also in North America, the Arctic National Wildlife Refuge boasts 1.5 million acres of coastal plain. Reaching from the Beaufort Sea to Alaska's Brooks Range and east to Canada, the majority of the plain is governed by native Inupiat tribes.
South America
The major coastal plain of South America is on the continent's Pacific coast in western Peru and Chile, where very little precipitation falls. Located between cold Pacific currents from the open ocean and the Andes Mountains in the East, this coastal plain plays host to Chile's Atacama Desert, the driest place in the world. There is almost no vegetation in the Atacama, and according to the National Geographic, in some areas rain has never been recorded in human history.
Southeast Asia
Between the Ghat Mountain Range and the Arabian Sea is India's Konkan coastal plain. Home to the densely populated metropolis of Mumbai, the Konkan has numerous seasonal rivers that swell with water during monsoon season. Another Southeast Asian coastal plain follows the South China Sea along the ragged Vietnam shore. More than 1,000 miles long, the width of Vietnam's coastal plain varies from only 25 miles to more than 300 miles at both the Mekong and Red River deltas.
Coastal Plain of the Past
Archaeological evidence suggests that at one point in time coastal plains reached places that are considered landlocked today. During the Cretaceous period, about 100 million years ago, a giant shallow sea bisected North America from the Gulf of Mexico in the United States to the Arctic Ocean. Marine creatures fossilized in prehistoric mud were found in Kansas and used in dating rock samples from the ancient coastal plain.