SR 163 and Arizona State Route 95 provide the next closest public Colorado River crossing to Hoover Dam.

Due to the restriction of commercial vehicles over the dam following the September 11 attacks, SR 163 comprised part of the required detour for truck traffic traveling between the Las Vegas and Phoenix metropolitan areas until October 2010, when the Mike O'Callaghan – Pat Tillman Memorial Bridge just downstream from the dam was opened to traffic.

From there, the highway negotiates some fairly steep mountain grades as it loses elevation heading east toward Laughlin.

Just outside Laughlin, the divided highway comes together and intersects Casino Drive before crossing the Colorado River and entering Bullhead City, Arizona on Arizona State Route 95.

At that time, SR 77 had an eastern terminus near the Bulls Head Dam (later Davis Dam) site and a western terminus at former State Route 76 (now an unnumbered road), which connected to US 95 north of the current US 95/SR 163 junction.