found: Work cat.: Roberts, Laura N. Robinson. Paleogeography of the Late Cretaceous of the western interior of middle North America, 1995:page 1 (Western Interior Seaway; A vast seaway occupied the Western Interior of North America during the Late Cretaceous, connecting the Circum- Boreal sea with the proto-Gulf of Mexico. This seaway formed during a time of maximum eustatic sea level for the Phanerozoic when water levels flooded the stable cratonic areas of the world. At its maximum extent, the seaway extended for 4,800 km from the North Slope of Alaska to northern Mexico and was approximately 1,620 km wide from central Utah to Minnesota
found: Everhart, Michael J. Ocenas of Kansas, 2017:p. 16 (Our discovery of the Western Interior Sea)
found: Hay, W. W. Physical oceanography and water masses in the Cretaceous Western Seaway, article in Evolution of the Western Interior Basin, 1993, viewed on Researchgate, April 20, 2018:(during much of the Cretaceous, the Western Interior Seaway extended 6000 km meridionally through the middle of North America, linking the polar and subtropical oceans. ... During times of peak transgression, the seaway was about 2000 km wide)
found: Wikidata(Western Interior Seaway; historic ocean; The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that existed during the mid- to late Cretaceous period as well as the very early Paleogene, splitting the continent of North America into two landmasses, Laramidia to the west and Appalachia to the east. The ancient sea stretched from the Gulf of Mexico and through the middle of the modern-day countries of the United States and Canada, meeting with the Arctic Ocean to the north. At its largest, it was 2,500 feet (760 m) deep, 600 miles (970 km) wide and over 2,000 miles (3,200 km) long)
