Drive north from Las Vegas on Highway 95 until you see the Lee Canyon turn off. Drive west on Lee Canyon Road until you come to the ski area parking lot. The Bristlecone Trail leaves from this parking lot. Follow the trail until you see the sign for the Bonanza Trail. Follow this trail until you hit the ridge line. The Bristlecones are along the ridge line for approx. 3 miles.
There is NO water and you are going to be hiking at the 10,000 foot level. There are lots of great vistas.
This is a picture of a couple of old Bristlecone Pine Trees trying to ink out an existance in a harsh environment. These trees are at the 10,000 foot level.