When I was on my trip to the Grand Canyon, we passed through an area near Mexican Hat Utah. The area was gravel road and had quite an elevation drop with 5 mph switchbacks. I got curious as to the exact elevation drop, and contacted the Utah Department of Transportation for information on this area. This is what I received back.
"What you experienced is known as the Moki Dugway. Our sign at the top warns drivers of an 1,100 foot drop over the next 3 miles. However, with pavement at the bottom extending to the beginning of the switchbacks, the gravel road now extends approximately 2.3 miles and drops from approximately 6,425 feet at the top to 5,588 feet at the bottom. I think you'll agree the 5 mph turn posting is plenty fast especially when you take a look at the scenery."
I have included the website for those of you that are interested. It is quite breathtaking, although I must admit that during the time I was riding it, I was more interested in keeping myself upright that the scenery.
http://community.webshots.com/slideshow/549895044vqbrnp?mediaPosition=1

Great pictures! Someday the wife & I plan to ride there.

Been there. Done that. Going down the big hill I met an idiot driving an RV UP the hill. No, it's not a two-lane road, but as I recall there was enough room at each of the switchbacks where one vehicle could pull over and let the other pass.

Somewhere out in that part of the country is where the final scene from Thelma and Louise was shot.

Those of you who would like to take a video ride down the Moki Dugway can crawl up in an 18 wheeler and do so at this link:

http://www.youtube.com/watch?v=f5mdW2Uro9A

Hold on to your knickers . . .

I don't know what was more disturbing, the view from the cab of the truck or the fact that some fool was filming that as they drove down!!! I hope it wasn't the driver filming it

Oh. My. God.

that'll get your adrenaline going. Fish Creek Hill (part of the Apache Trail in AZ) drops you 900 feet in a mile (10% grade bumpy (washboard) dirt road). I've riden the entire apache trail on my R* (not the smartest thing I've done).

Here's some links:

http://www.amwest-travel.com/awt_apachetrail.html
http://virtualguidebooks.com/Arizona/CentralArizona/ApacheTrail/MiddleFishCreekHill.html

And to think... all that was cut out by the great waters of Noah's Flood 4,600 years ago! Wow!

I'll leave the bike at the top and take a Mule ride down. I'm a bit crazy but I'm not NUTS! Yikes I live in the flat lands, to me a hill is a road that you can't see the next mile marker.

Hey Heavy thanks for posting that link, that was really cool.