I spent several weeks exploring this very area--Jarbidge, NV--last summer in my old Land Rover. It's no joke. There are many Forest Service "roads" that are completely impassible, even by a very capable 4WD vehicle such as the one I drive. I spent over a year planning routes before I took my trip. I had plotted out a route from Jarbdige to Silver City, ID that's completely on dirt and--incidentally--probably crossed some of the same roads this couple took. I was traveling with other trucks and we ended up driving through ankle-deep mud and thick tamarisk trees before giving up. What looks like a passable route on USGS topos and Google Earth doesn't always pan out.

You can see some photos from the trip here:

https://www.flickr.com/photos/defender90/albums/721576543876...

I also did a detailed write-up with photos:

http://www.expeditionportal.com/forum/threads/146545-The-Owy...