It travels along the northern edge of town before having an intersection with SR 211 (Old US 51), just northeast of downtown, before leaving Newbern and continuing east through farmland and rural areas to cross into Gibson County.

The highway then narrows to 2-lanes as it bypasses Trenton on its eastern side, where SR 54 joins the concurrency.

SR 77, becoming a primary route at this point, continues eastward to pass by the Gibson County Airport before entering Milan.

They pass through a neighborhood before having an intersection with SR 425 (Middle Road) before leaving Milan and widening to a divided highway for a short distance before narrowing to 2-lanes and crossing into Carroll County.

The highway then enters a business district before coming to an intersection with, where it reaches the northern terminus, US 641 (SR 69) on the southeast side of the city.