My wife and I had a completely different experience in Saline Valley than Dave but we went in late May rather than August which allowed us to avoid the extreme heat, we were aware that cell phones don't work there, we had maps, GPS and amateur radio gear with us that could have been used for communications and we were prepared with food, water and temporary shelter in case we became stranded. We drove a Subaru Outback but road conditions we experienced would have allowed a high clearance pickup or SUV with two wheel drive and posi-traction or limited slip rear end to negotiate the roads. Road conditions may change depending upon the weather and maintenance by the park service.
We left the Panamint Springs Resort (lodging, restaurant, supplies, fuel and camping with electrical hookups) headed west on CA-190 and drove up Darwin Canyon into Darwin past desert scenery and relics of the area's mining heritage. If one desires you can stop in the Darwin Post Office and send your mail and letters to friends and family with a rare Darwin local post mark, open 8-12 Monday through Sat, 760.876.4407.
We left Darwin on the paved road and took CA-190 east to the Saline Valley Road turnoff. The first 8 miles or so are old broken desert macadam followed by another 8 miles of dirt road to the top of Grapevine Canyon and the primitive camping that Zep mentioned. I might consider taking our CCD in as far as this point but I would not try to drive down Grapevine Canyon into Saline Valley even though it could be done. I would try it with our Cherokee and 18 foot Traveler once it has been rebuilt.
Temperatures were moderate, high 80s until we reached the valley floor where they climbed to the low 90s. I echo Zep's comments, the views across Saline Valley and of the desert mountains that form the boundary of the valley are spectacular! The Salt Tram ruins equally so. I believe the tram, hauling salt, had the greatest elevation change of any in the world, from approximately 300 feet on the valley floor to over 8000 feet at the top of the Inyo Mountains and then down to approximately 1000 feet in Owens Valley where the salt could be shipped to LA markets.
At this point temperatures climbed into the high 90's and continued to climb to 107 when we reached the Warm Springs, a somewhat permanent camp of eclectic folks who appear to live here year-round. This desert encampment is a relic of the Bureau of Land Management control over Saline and Eureka Valleys before they were brought into the National Park system. Warm springs includes many, you guessed it, warm spring pools and baths for leisure and a oasis of palm trees and grass supplied from cooler springs up a side valley. Military surplus shade netting provided a cooler place to sit, relax and enjoy lunch during the hotter part of the day.
I will admit that temperatures climbed while we ate lunch. It was 113 when we got back in the Subaru at ~1PM but quickly dropped back into the 90s as we drove out the north end of the valley. The north exit is deceiving, it is about 10 miles long and doesn't appear steep until halfway up when you notice your water temperature climibing; we turned of the A/C and stopped once or twice to make sure the Subaru didn't overheat.
Once out to Death Valley Road you have two choices, paved road west to Big Springs or east on paved and then desert dirt road. The east route rewards you with more desert views of the Eureka Valley and the Eureka Sand Dunes after which some of the worst washboard road I have ever been on take you through the Last Chance Range of mountains back to paved roads in Death Valley near Ubehebe Crater and Scotty's Castle. From here it is all paved roads through Death Valley back to Panamint Springs. Stovepipe Wells is another good starting point for this loop (fuel, lodging, supplies and camping) as is Mesquite Springs Campground near Scotty's Castle but no fuel or supplies when we passed through last July (Gas station at Scotty's Castle was still close). This loop is about 200 miles long, about 100 being paved and 100 being dirt.
Another scenic loop can be made by turning onto Hunter Mountain Road instead of going north down Grapevine Canyon. This route takes you east and then north into Hidden Valley to Tea Kettle Junction at the intersection of Racetrack Valley Road. A short drive south brings you to the Racetrack, the large dry lake or playa where wind and other forces cause large rocks to move and leave telltale tracks on the dry lake bed. The best way to return is to backtrack on Racetrack Valley road north past Tea Kettle Junction to Ubehebe Crater near Scott's Castle.
We would highly recommend that others go there for the desert experience which include views of the historic structures provided that they carry water, equipment and supplies in case they have a breakdown.
While not required, having your amateur radio operators license and good radio gear can provide communications when other commercial systems fail or are not available. If not leave word with someone at the campground, park service or lodging about where you are going and when you will be back. Another improtant aspect is plan your trip
. I highly recommend having both the National Geographic and Tom Harrison Maps of Death Valley and a GPS. Every road that I described was in the mapping on our Garmin 2620 GPS. If people will PM me with an email address I would be happy to email you the route and waypoint file of both of these trips.
These web sites and photos might convince you become a Desert Rat also:
Death Valley Map:http://www.nps.gov/deva/planyourvisi...d/DEVAmap1.pdf
Death Valley Backcountry Roads Map: http://www.nps.gov/deva/planyourvisi...%20Roads-2.pdf
Saline to Owens Valley Tram (Excellent Site): Saline-to-Owens-Valley Tramway