What is the largest fault line in US?

[eSineM]

THE NEW MADRID FAULT SYSTEM EXTENDS 120 MILES SOUTHWARD from the area of Charleston, Missouri, and Cairo, Illinois, through New Madrid and Caruthersville, following Interstate 55 to Blytheville and on down to Marked Tree, Arkansas. It crosses five state lines and cuts across the Mississippi River in three places and the Ohio River in two places.

[mc1962]

Here in California we have many fault lines - one day we are going to have the "Big one" and Nevada will have ocean front property (LOL) 

[eSineM]

I really don't think the "Big one" is gonna be big as they are preaching... The San Andreas Fault has hundreds of quakes everyday, therefore releasing aload of pressure, ya know... now that New Madrid Fault Line is way over due, just like the Haiti shake..

[cynybiny68]

I don't know which is bigger, but I do know that I don't like them no matter where they happen.

[nauticalstar]

I think the San Andreas fault is the longest fault line in the world.  It is 625 miles long.