The northernmost mile or so is shared with U.S. Route 97 Business, which departs from OR 39 and heads downtown via Esplanade Street.

The East Side Bypass ends at an intersection with South 6th Street, in the eastern suburb of Altamont.

OR 39 shares an alignment with OR 140 for about two miles (3 km), until OR 140 west diverges once again as the Southside Expressway.

OR 39 then leave the Klamath Falls metropolitan area, and heads south-southeast for about 12 miles (19 km), until it reaches the town of Merrill.

The highway then turns due east, running parallel to the California border.