Get a San Bernardino County AAA map. They show good detail of the roadways in that area. I-15 isn't the only way. You can go from Hesperia to the Nevada Line and maybe take a few miles of freeway. Basically, you'd follow old US 66 (National Trails Highway) to just east of Barstow, then a couple miles of freeway, then National Trails Highway east to just past Amboy, then Kelbaker Road north to Cima Road, then Cima Road to Morning Star Mine Rd, then Ivanpah Rd, then Nipton Rd, then Nipton Rd to I-15, then I-15 north to north of Primm (old Stateline), NV to the second exit in NV. There, you take NV 604 (old US 91/466 and Las Vegas Blvd). Pretty easy from there.
The route takes you through the Mojave National Preserve. Kelso, where you meet the Cima Rd, is a good place for water and I think now has food. Your only real alternates are old US 91 (Yermo Rd) along I-15, but that only goes as far as Field Rd, and way east to US 95, which is very busy.
Last edited by sd_mike; 12-09-09 at 12:22 AM.