Here ya go...just released nature article on continent drift caused by mantle intrusions...
http://www.nature.com/news/2011/110706/full/news.2011.400.html?WT.mc_id=TWT_NatureNews&utm_source=feedburner&utm_medium=twitter&utm_campaign=Feed%3A+yahoo%2FqUaz+%28Nature+news%29&utm_content=Twitter
I've notice a lot of small earthquakes forming lines that point toward Yellowstone.