The route was originally part of US 95 until the highway was realigned following the completion of Interstate 11 (I-11) around Boulder City.

The entire route of SR 173 is also part of the Veterans Memorial Highway.

[2] State Route 173 begins at an interchange with I-11/US 93/US 95 approximately 5 miles (8.0 km) southwest of downtown Boulder City.

Proceeding northward, the highway ends at an interchange with US 93 Business.

[1] US 95 was rerouted onto the Boulder City Bypass concurrent with I-11 upon the completion of Phase 1 on May 23, 2018, and the new state highway was designated over the old route.