During Christmas break of 1987 I took a mountain bike ride around Death Valley, California. I'd never want to go any other time. They say the temperatures normally get up to 110 degrees in the summer but that its gotten up to 134 degrees; it was hot enough at Christmas time! There are facilities all around the park so water wasn't a problem and there's a couple of campgrounds in the park (camping is prohibited anywhere else). Bring some money - they charge a fee to get into the park and for camping. It ain't cheap!