Los Angeles, CA to Boulder, CO buses and trains from $153

Or, see buses and trains from Boulder, CO to Los Angeles, CA.
Here are some trips other travelers have found on Routefriend.
21h 15m
1 stop
1d 1h
1 stop
1d 5h
2 stops
GotoBus Amtrak
1d 8h
3 stops
GotoBus Amtrak