State Road 550 exists in two portions. The western section is completely within Knox County and has a western terminus east of Emison at U.S. Route 41/U.S. Route 150 and runs southeasterly to the U.S. Route 50/US 150 concurrency in Wheatland.The eastern section terminates at both ends at US 150 in Martin County between Loogootee and Lacy.