Washington State down to Northern California has marked tsunami evac routes and practice evacuations of schools and such. Hawaii and Alaska of course have a system.
However there's some evidence that there's a local tsunami danger in Southern California......but not much has been done to set up any warning system there.
We have had tsunami alerts in the Monterey Bay after some earthquakes, but nothing ever came of them.
Supposedly we have a National Tsunami Hazard Mitigation Program. Here is a link to a study from 1998, I am not sure of the current state of the project.
http://www.pmel.noaa.gov/tsunami/dart_report1998.html