Interstate 270 (
I-270) makes up a large portion of the outer belt
freeway in the
St. Louis, Missouri metropolitan area. The counterclockwise terminus of I-270 is at the junction with
I-55 in
Mehlville, Missouri; the clockwise terminus of the freeway is at the junction with I-55 and
I-70 north of
Troy, Illinois. The entire stretch of I-270 is .