Interstate 15 (
I-15) is an
Interstate Highway in the U.S. state of
Nevada that begins in
Primm, continues through
Las Vegas and it crosses the border with Arizona in
Mesquite. The freeway runs entirely in
Clark County. Many motorists use I-15 to visit Las Vegas, as it is the only primary Interstate Highway in the city. The highway was built along the corridor of the older
U.S. Route 91 (US 91) and
Arrowhead Trail, eventually replacing both of these designations.