Amtrak
Amtrak
http://www.amtrak.com/
Big Blue Bus
Big Blue Bus
http://www.bigbluebus.com/
Green Tortoise
Green tortoise adventure travel offers low-cost adventure travel camping tours in remodeled sleeper coaches to outdoor destinations in north & central america, camping & hiking while visiting national parks as well as undeveloped wilderness areas.
http://www.greentortoise.com
Greyhound
Greyhound
http://www.greyhound.com/