Thanks, all.
Eric, it is a long drive. From the pavement on Badwater road it is 23 miles of dirt road (Warm Spring Canyon road) to Butte Valley, the last 10 miles of which are very rough. We started out at 3:20 am since we had been asked to budget at least 2 hours for just this stretch, but my guide flew through in 70 minutes in his 4x4 Sports Wrangler. Being out on a backcountry road in Death Valley in pitch darkness is an experience not to be forgotten. It takes around an hour from Furnace Creek to get to the Badwater road junction before the dirt road begins, so normally it is a 3+ hours one-way. The other route is via Mengel Pass and Goler wash through the Panamints, and that is an obstacle course in the best of times.