The road passes through some of the most spectacular and diverse scenery in the country, including the Mojave Desert, the Wasatch Mountains, and the Rocky Mountains. In the south, it begins in San Diego, California, near the border with Mexico.
It starts in the north at the Canadian border, connecting with Alberta Highway 4 at the Sweetgrass–Coutts Border Crossing. I-15 is a major highway running north-south and running 1,433 miles in length.