The Trans-America Trail (AKA: the “TAT”) is a west bound dual-sport motorcycle ride across America.

The Trail starts in Southeastern Tennessee, and ends at the Pacific Ocean in southwestern Oregon – nearly 5,000 miles of mostly off-pavement riding.

Ever dreamed of traveling cross-country on your motorcycle, seeing sights you’d never see from a car, and meeting great people along the way? Sam Correro had that dream and made it a reality by creating the Trans-America Trail. Now any dual-sport motorcyclist can make this amazing adventure, thanks to Sam’s meticulous mapping of the nearly 5,000-mile route across America.

http://www.transamtrail.com/

I know its been done with side by sides
http://www.rzrforums.net/utv-inc/41286-4800-mile-utv-ride-across-america.html

http://www.commanderforums.org/forums/utv-inc/1719-4800-mile-utv-ride-across-america.html

Attached is the map you can open in Google Earth