The Pacific Coast Migration Model is a theory concerning the original colonization of the Americas that proposes that people entering the continents followed the Pacific coastline, hunter-gatherer-fishers traveling in boats or along the shoreline and subsisting primarily on marine resources.
The PCM model was first considered in detail by Knut Fladmark, in an article in American Antiquity which was simply amazing for its time. Fladmark argued against the Ice Free Corridor hypothesis, which proposes people entered North America through a narrow opening between two glacial ice sheets. The Ice Free Corridor was likely to have been blocked, argued Fladmark, and if the corridor was open at all, it would have been unpleasant to live and travel in.
Fladmark proposed instead that a more suitable environment for human occupation and travel would have been possible along the Pacific coast, beginning along the edge of Beringia, and reaching the unglaciated shores of Oregon and California.
The main hitch to the PCM model is the paucity of archaeological evidence for a Pacific coastal migration. The reason for that is fairly straightforward--given a rise in sea levels of 50 meters or more since the Last Glacial Maximum, the coastlines along which the original colonists might have arrived, and the sites they may have left there, are out of present archaeological reach.
Sources
This glossary entry is part of the About.com Guide to the Population of America and the Dictionary of Archaeology.
See the Kelp Highway Hypothesis, the Ice Free Corridor and the Solutrean connection for additional hypotheses concerning the population of the Americas.
Fladmark, K. R. 1979 Routes: Alternate Migration Corridors for Early Man in North America. American Antiquity 44(1):55-69.
Gruhn, Ruth 1994 The Pacific Coast route of initial entry: An overview. In Method and Theory for Investigating the Peopling of the Americas. Robson Bonnichsen and D. G. Steele, eds. Pp. 249-256. Corvallis, Oregon: Oregon State University.
